Yea, I’m not sure how accurate some of the methods he’s showing are. I have a pretty large collection of tech books and I had a look at the gluing after he said it. My O’Reilly, Springer, No Starch, Pragmatic and CRC press books all have pretty consistent binding.

Whereas I have some manning books like the Grokking series that I buy directly from them when they have those Black Friday sales and the glue looks pretty similar to the counterfeit he’s showing in the picture.

That said I usually try to buy from sold by amazon or directly from manning or no starch when buying new. Manning has some great topics and the quality of the content is pretty good too.