Many of you may know Dave Chesson. He is a wealth of knowledge for anyone looking for information about publishing. He also has some products to sell related to that as well (which I am not endorsing here but I do trust him – he’s been around the book world for quite a while). Part of the reason I trust Dave is because he gives a lot of good information away for free. This post is an example.
I have done Amazon ads and I’ve hired others to do it for me as well. Both times I’d say I came out about even in the money I spent and the money I gained. It gave me more readers (not a lot, and not sure that translated to purchases of any of my other books) but I’m still on the fence whether it was worth all the time I spent on doing it myself, since I just broke even.
If you’ve even tried ads yourself, he’s right, key words are KEY! (pardon my pun). His post helps you a bit in that direction. (link below)
“Learn how you can create a list of profitable Amazon ads keywords for your book advertisements and start earning now on your ads!…”
Source: How to Find Profitable Amazon Book Advertisement Keywords 
Where Publishing Dreams Become Reality
Laurence O’Bryan’s of Books Go Social post on Amazon ads has some helpful information. Most notably the link to kindlepreneur and a free book description tool. A good book description is very important!
Laurence mentions that it’s important to have some good reviews – I’d suggest at least 10, but more is better. If you’re going to spend money on advertising, having reviews will help you spend your money more wisely. Remember, all reviews don’t need to be 4 or 5 stars. In fact, I think the reviews look more legitimate if there are a few 3 star reviews, not that you have any control over this. I just mention it because not everyone who reads your book will LOVE it and potential readers know this, so don’t worry when you get a few 3 star reviews. Hopefully your average is 4/5 or above.
I also agree that you shouldn’t spend more than you can afford. Pay attention to the ads – what they are charging and what money are you making. Keep in mind, the money they say you are making doesn’t take into account the discount – the 70% or 30% that Laurence mentions (item #5).
Note: I am not endorsing Books Go Social or the things they want to sell you in this post, but I know they are a good company and I do think they have author’s interests at heart – just below staying solvent (as all companies). I have not tried their free AMS ad course, so I can’t speak on that, but I think your keyword choice and your ad copy are two things that are very important with AMS ads. Those that can use computer-generated ad key words have an advantage. Unfortunately, that is not most of us, so we have to do our best.
Anyone who tries BGS free course, please share what you think. If I eek out some time to do it myself. I’ll also share what think.
Keep on Keeping on!