So I obtained a free $100 advertising credit for Facebook (just search for the Visa Business Network and register and Facebook sends you a $100 coupon code)... and I set up an ad campaign for my iPhone game, Rogue Vertex. I set it up to run over 4 days, spending $25 each day. The number of impressions is irrelevant (but it's over 500,000). I got about 52 people clicking the ad every day. So about 200 people clicked on the ad. How many of them translated over to sales? I'll share... For each day the campaign ran, Rogue Vertex had 0 sales. As I expected, advertising was completely ineffective. Most people don't even click on ads, and the few that do probably did it by mistake lol. I lost nothing because the ad campaign was free... but now I know not to be tempted by advertising in the future.