I have been using their service a few times/ for a while now. I have to say it is not that good. I followed their rules when it comes to reviews and ratings. So let's say I ordered 500 installs with 1-3 ratings and 1-3 reviews. Both rating and reviews with most apps were removed the next day.
I asked also for a mix of bad ratings and reviews that matched that. So I get like an X amount of bad ratings, but the reviews were very positive, like: This is the best app ever! Or usually I don't like these kind of apps but this one is good! It is just weird to see positive comments with 1 star ratings.
I mailed several times to support and ask if they could change the reviews since it won't look natural. 1 star ratings with positive reviews? Weird. But has not heard from them since.
Also on Facebook they promote their services with features that has not been added yet. When I ask them why promote something you don't have (yet) they replied it will be in the future...
This is the first time I gave a service/ product a "bad" review since most services I used were good and knew what I bought.