Guusje photo

The librarian with a six-figure online business


A Quick Announcement:  I’m excited to report that my online book flipping software will be launching on December 15!  This software will help you find cheap Merchant Fulfilled books to flip via FBA.  Anyone who signs up for email updates will have access to a few early adopter incentives when the software goes live.  Click here to learn more and join the email list!


Background Story:

I first met Guusje through the BooksellersFBA Facebook group.  Her love of books is evident, and she willingly shares her knowledge with anyone who will listen.  If you join this group, you’ll see her name pop up all over the forum:Screen Shot 2015-11-23 at 11.21.56 PMI’ve benefited often from my interactions with her.  What I appreciate most about Guusje is her calculated approach to her business.  While most sellers subscribe to the “bigger is better” mantra, Guusje is calmly running her own “small” business, with an inventory no larger than 1,500 items.  But don’t mistake small for unimpressive – Guusje is on pace to reach $125k in combined sales on Amazon and eBay in 2015!  Books account for roughly 40% of her sales.

The best part?  Guusje willingly agreed to share some of her insights with all of us today.  Here’s the interview:

Caleb:  Books are ingrained in your background.  Tell us a little bit about your experience with books and libraries throughout your career.

Guusje:  I’m a librarian by education so I have 40+ years of experience connecting people & books.  I’ve been both a public and an elementary school librarian.  Not only did that immerse me in books, it also gave me a good grounding in customer/public service.  Those skills have been invaluable with Amazon.  Needless to say I’ve always been a voracious reader.

How long have you been selling on Amazon?  What sorts of products do you sell?

I’ve been selling on Amazon and eBay since 2000.  Originally I just sold books.  I started dabbling in Retail Arbitrage when the scouting tools came on the market and lots of new folks joined the book business.  That was also about the time Chris Green debuted ScanPower and released his book “Retail Arbitrage”.   At the moment I am about 50% books and 50% RA.  The bulk of my RA is clothing and shoes.  I also sell on eBay.  Some items I list directly on eBay & I use a program called JoeLister to list some of my Amazon inventory on eBay.

How big is your current inventory, and do you have aspirations of scaling your business or intentionally keeping it a smaller operation?

I have the world’s smallest inventory – it’s never topped 1,500 items (and not many multiple SKUs).  I sell about as many items as I send in every month so it doesn’t seem to grow.   I have no interest in warehouses or a large scale operation.  I spent 40 years working with and managing people and don’t want to ever do it again.  At this stage in my life I do not want to be responsible for another person’s mortgage.  I also love the flexibility of being a one person operation.  My wife is often invited to play in golf tournaments and I’m able to tag along.

Where is your favorite place to source books?  Least favorite place?

My best buys come from estate sales.  I pay more per book than I would at a thrift store but when I find a good one I come away with 20 – 200 very good books. They are clean and there aren’t any price stickers to remove. The downside is that you have to “kiss a lot of frogs” before you find a prince.  I subscribe to and carefully scrutinize the pictures.  I’ve discovered that by looking at the furniture and art can tell you a great deal about what kind of books the person owned.  

Oddly, my least favorite sources are Friends of the Library sales.  I don’t like the competitive, cutthroat atmosphere.  The FOL groups in my area either sell on Amazon or sell to BetterWorldBooks so they aren’t a reliable source of inventory.  

What scanning setup do you use – which app, scanner, etc. do you use?

When I first started there weren’t any scouting tools!  My first “app” was ScoutPal on a flip phone.  You had to type in the ISBN – which, while time consuming, was also a very good education since you had to physically open each book.

I then switched to ASellerTool with a PDA & scanner.   I used that till Chris Green brought ScanPower to market. It came out about the time I started doing RA and I needed something that had access to the entire AZ database.

That’s the product I’m currently using – I have an iPhone 6 and a Bluetooth scanner.

My first listing program was Art of Books – that was back when I Merchant Fulfilled everything.  I switched to ScanPower when I started doing RA.  I still use it to list.  I loathe listing directly on Amazon – it’s so time consuming.  I list using a plug ‘n play scanner.

I am extremely focused on data when it comes to running my business, and I use sales rank and current pricing to aid me in making book purchasing decisions.  One thing that intrigued me about your purchasing philosophy was how little attention you pay to the sales rank.  You often talk about how it’s more about the publisher or the subject matter rather than the sales rank.  Can you elaborate on those points?

Data is my weak point.  I’m not good at it (I grew up in the pre-Excel days!) and it both bores and baffles me.  I know I should do better but I also know it’s sometimes difficult to teach an old dog new tricks.   Since I’m a one person operation I stay away from bulk buys and focus on the long tail books.   I live in Houston so I’ve developed a niche in petroleum, engineering, and oil & gas books.  I find other sellers often pass them by because they can look formidable – not to mention boring.   I’ve learned who publishes books that hold their value and I look for industry buzz words.   The books are long tail – ranks of 3, 4, and 5 million are not uncommon but they sell for good money.  Often the buyer is using a company expense account and isn’t fussy about the price.  They also want it yesterday so FBA is a perfect fit.   Many of the books are bristling with tables and charts which don’t translate well to an e-book format.  The data doesn’t change as quickly as medicine so the books hold their value.

What specific publishers do you look for?

Pennwell, Gulf Coast, Wiley, AAAP (American Association of Petroleum Geologists), SEG (Society of Exploration Geophysicists), and academic presses.

Without giving away all of your secrets, do you have a few book subjects that get you excited?

Seismic stratigraphy, petroleum processing, well head maintenance, well log interpretation, gas well testing, fracking, natural gas well maintenance, petroleum plant maintenance… And no, I have no interest in reading any of these books!  And I have no background in the field.  I have a BA in History, a BA in Education and a Masters in Library & Information Technology.

How do you tell if a highly-ranked book has a decent chance of ever selling again?

I use my bookseller’s “spidery sixth sense”.  I started selling prior to the debut of CamelCamelCamel and Keepa and don’t consult them as often as I should.  Since I have 15 years of bookselling under my belt my sixth sense is pretty good.  I also price very, very competitively.   Since I sell long tails I want to be sure I’m the one who snags the sale when that lone buyer comes along.  I regularly undercut the mega sellers by $100 or more and find that often gets me a sale.

Are there any other tips or tricks you’ve learned that you’d like to share with The Book Flipper Community?

  • Buy better books!  It’s almost impossible for a solo bookseller to make money selling books for less than $9.99.  There just isn’t enough profit.  The FBA fees will eat you alive.
  • Don’t get fixated on paying “only 25 cents” per book.  If the profit is there, don’t be afraid to “up” your buying price.  I’ve paid as much as $40 for a quality book.
  • Don’t get hung up on rank.  Look at the subject and think about who your buyer is.  A 20-year-old textbook isn’t likely to sell, neither will a 20-year-old medical book.  A 20-year-old book on “Fashion from 1700-1800” likely will.  
  • Don’t scan with ear buds and buy strictly based on what your scanner tells you.  Take a second to actually look at each book and think about why it is or isn’t a good buy.  That’s the only way you’ll ever morph from a “books as widgets” seller to a bonafide book seller.
  • Lastly, value your time.  Yes, getting 1,000 books for free can seem like a very good deal.  But if they are junk books you’ve just wasted hours of time that you could have spent scouting for better books.


  1. Really interesting interview, thanks. Getting to know a niche publishing area, as Guusje has, and specializing in long-tail books with a high profit margin (even if they take longer to sell) instead of endless $9 and $10 profits seems to be a good business model for solo operators.

    • Indeed it does! As a solo operator myself, I’m toying with the idea of avoiding $8-11 books moving forward based on some data trends I’m seeing in my own sales figures.

  2. This was a very interesting interview, Caleb. A special thanks goes out to Guusje! It was great to hear from someone in my age group who is successful in this business, and having fun doing it.

    For others of the gray-haired generation, I might suggest they remember to find out about senior discounts at thrift shops. One shop I go to has a day each week when I get 40% off books, another has 60% off. What a deal! And, a few days ago, I found out about a sale at my alma mater and was told that the first day was limited to professors and students with ID cards. I asked if I could come since I was an alumna. I was told that if I had my old ID card I could. So I dug through my stuff and dusted off a 45-year old card. It paid off because I was the only one there with a scanner, and it was my best sale yet.

    • That’s great advice! My best sale was my alma mater library sale that wasn’t advertised. I’ve also thought about finding some senior citizens to help me with buying books at thrift stores since they can get some pretty hefty discounts 🙂

      • I’m old enough to use the senior discount on the weekly senior discount days and it helps with the margins. Some other thrift store chains (like Epic Thrift) offer a discount to current military and veterans, so if you have a veteran card always take it with you. Goodwill and others also mail out monthly discount coupons (here, for 20% on purchases over $10) that can be used over and over, so sign up for their emails and always keep a copy of the monthly discount coupon on your phone and maybe a hardcopy print-out.

  3. I’m wondering how many books must be scanned in order to find one like she talks about. I feel like I’m scanning about a hundred in order to find even one that has any potential at all.

    • Do you sell FBA? A lot of books are worthless and you’ll have to train your eyes to pass over these books and hone in on books with potential value. I probably find a quality book 1 out of every 10-20 books that I scan.

  4. This is great stuff. I’m new to this business, Caleb, and your process gives me hope. I worked as a book buyer in an independent shop for years, so I’m entering at (Peter Valley’s?) “Level 3,” saving me time by relying on my hunches instead of scanning every book and leaning on the numbers. So far it has been paying off, but I’m encouraged to learn more from your blog. Thanks!

  5. I’m glad I came across your post! I am not a book flipper myself, however, my in laws are and I will be sure to share this with them! Great insight. ????

  6. Great blog. I think the most valuable insight is that FBA booksellers really help their efforts by developing their own anthology of books, like the petroleum books mentioned in the blog. Doing that allows them to spot buried treasure immediately and without scanning. For instance I ran across an oil and gas accounting book for 25 cents at a book fair a few weeks ago. It sold within a week for about $50.
    Also, if the FBA seller already has some niches in which she has expertise, she can build her anthology on those.

  7. Wonderful interview! Thanks for all your information and tips! I’ve been dabbling in bookselling for years and never had any information like you are passing on. I’m enjoying it all!

  8. Great interview! Sometimes it’s good to learn from those who had to rely on their sixth senses before all the fancy technology came into existence 😉 I love books, so I don’t find it such a chore when scouting for inventory, even books on arcane subjects. Like you and Guusje say, you do develop a sixth sense after awhile, which helps you scout a lot faster instead :0)

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