Can't seem to find my message here, it's gone, but I got your replies. It's understandable to be skeptical, and the real reason is because it's almost pointless to advertise the way most people do it. People on this site go about advertising the wrong way. It's better to advertise yourself as a good person who will help people and be friendly instead of advertising your work, because if you just advertise your work saying "hey read this" it makes the person you're advertising to feel like a number, not someone you value. The reason most advertising books don't work is because people just go to comment on them to get their book read, but they don't look for books to read. It's a good idea, in the wrong format. Because the books WILL be seen by app audience, but readers generally won't read through all the comments just to find something.
My advertising book is different. Instead of just letting people spam away with advertisements, I encourage people to post them for a chance to win a full-page advertisement in the book itself. That way, if people see the book, they get to actually read through single advertisements on each chapter instead of going through tons of ads in the comments. It's a contest, of course, I only pick one winner a week, but since not many people have been entering I've been rolling over all contestants to the next week. Like I said, you can feel free to enter again, please just read the first two chapters to understand how it works.
To be honest though, if you want people to read your work, just read other people's work and comment on it. Help them out, make friends, and that's how you'll get ahead. My story OathBlade has almost 200,000 reads right now, and not a single one was gotten from asking others to read. It all came from patience and hard work to make the book good. There's no fast-track to getting reads, but if you make friends and help others, you're more likely to get help on more than just the one book you're advertising.