We once tried buying google ads directly on highly targeted keywords. We spent a small amount of money, but it resulted in no sales at all. Other attempts at a

We once tried buying google ads directly on highly targeted keywords. We spent a small amount of money, but it resulted in no sales at all. Other attempts at advertising, via tap joy, etc, also produced almost no positive results. Using pay-per-install, you can have thousands of people download your app (for thousands of dollars)... but nearly none of them will ever launch it again. I think they're also the same people who download dozens and dozens of apps, more than they can keep track of.