The world of fake
Very soon after I started making my own purchasing decisions as an adult, I discovered a simple rule: all advertising contains a falsehood.

If you receive a letter telling you that you won a lottery or if there are "funds for you to collect", it is a blank lie.

If you are in a supermarket and you see "red ripe tomatoes" written on a shelf, the tomatoes are likely to be whitish-pink and tasteless. (The taste of tomatoes seems to have been destroyed by deliberate breeding: https://www.seattletimes.com/life/food-drink/modern-tomatoes-flavor-stolen-by-red-ripe-mutation-study-shows/ )

If you see a large corporation promoting "Don't be evil" as a company value, it's a sure sign that the corporation is deliberately doing what it considers as evil.

If you see 15 Amazon book reviews all saying how great the book is - most likely, all these reviews are fake. Here is an example: https://www.amazon.com/Analytical-Dynamics-Approach-Udwadia-Hardcover/product-reviews/B011MERKG4/ As we can read in the first (negative) review, this book used to have 14 glowing reviews! The fake reviews directly and somewhat clumsily over-praise the book's authors. Now it has only 5, as Amazon removed most of the fake reviews.

Today, we have entire websites with completely fake content.

Example: https://ebook.pdfbookslibs.com/1523750.FUNCTIONAL.pdf

This is supposedly a freely downloadable e-book on functional programming. Supposedly some users have posted comments saying how great this is, how they could download this book quickly in ebook, mobi, etc. formats. One user wrote: Finally I get this ebook, thanks for all these Functional Programming: Practice And Theory I can get now!

Clearly, all of this is fake. The book with the pictured cover does not exist in any format, and those users do not exist.