Is it worth it to buy incentivized downloads on Google Play?
Google publishes the number of downloads you have for your app so it’s advantageous to have high download numbers. If you have a bigger budget, it makes sense to buy incentivized downloads purely to move the number up and down. You don’t want to lose a customer just because they judged your app by the low number of downloads.
For one of my clients, we bought 5,000 downloads for $500 (about $.10 CPI) and we did through the Philippines. We drove the 5k downloads on Sept.19 but almost everybody uninstalled eventually so you need to foresee that you are not really going to get good users through this method. But the idea about buying incentivized downloads is that you can get cheap downloads while running other campaigns. You can combine the two to spike the stores. This is the approach which you need to take.
I also checked data from App Annie to see if our drive for downloads improved our keyword ranking and saw that there was a slight increase, albeit as very small one.