Here is a list of the top Paid Book Promo sites of 2017.
All of the sites listed here come from my personal experiences using them as well as things I've heard from other authors. In this case, everything is going to be devoted to sites that promote paid promotions (there is another post for free promotions here) but that doesn't necessarily mean how much the actual book needs to cost to be promoted.
If you would like to add your site to the following list, please contact me here and I'll get you added as soon as possible!
Here are the 5-Star companies worth checking out. These are all highly recommended and should be submitted to at the first and every opportunity:
Here are the 4-Star companies that I regularly use to promote my books. You should probably still submit to them, though keep in mind that there are some caveats to this: they might not be great for a certain genre, or their results could seriously diminish over time.
In general, I would recommend all of them here, and if you check out my individual reviews of each one of them you can find out more about the good and bad parts of their promotional services.
Now onto the 3-star promotional sites: these ones are still decent and net some results, but they will almost never actually return results matching their cost. You can still use them if your goal is ranking or finding readers, but don't expect to make money from them.
The individual reviews linked to below will give more explanation of why they are good or bad and what to expect when you sign up for them. I've used each of these services multiple times, though many of them I've stopped using in recent months. If I end up using them again I'll make sure to update the posts, though, to keep them fresh!
These are the 2-Star rated sites. I don't rate things any lower than that, and in general these are services I strongly recommend skipping over and not using. Their negatives often outweigh their positives and they are just sinkholes for money and traps for indie authors.
I don't recommend these services, though they can be good for some authors. They are off my list of promotional locations and in some cases are more expensive than five-ten other services.
There you have it. That is the list of book promotional sites that I've used in the past and whether or not I would recommend them for indie authors hoping to get an edge. Some of them are 100% not recommended, but others might actually be worth checking out or completely necessary, and hopefully over time you can develop your own list of recommended services (and horror stories to help other authors avoid bad ones!).
Feel free to contact me if you feel I've made a mistake or there is a problem with one of my reviews. I'm always open to suggestions and don't mind making minor mistakes. However, if you are a service and don't like the review I've given your website, please don't contact me to complain. I'm just one author giving my opinion and recommendation.