Yes, I just bought a beautiful place in Santa Monica, paid for by Facebook ads kicking #$%$ and the subsequent upward explosion in stockprice.. Oh, that's not what you meant. Never mind. As you were.
At best, mobile advertising is counting on about 1 out of 1000 people clicking on an ad and installing an app. It may not sound like much, but if you pay $2 CPM for those impressions, and the LTV of that user is greater than $2.00, you've made money. And for games like Candy Crush or Clash of Clans, LTVs are much greater than that.