Here is an offline method that I learned from a buddy of mine that did pretty well with it and it was pretty easy to do. NOTE: I don't have any results personally with this method...but I've seen his account from this one method and it definitely works.
What this method entails is having you or someone hand out flyers at a major sporting event....baseball or football. And hand out the flyers as people walk into the stadium to before the game to sit down.
The flyers will say something like...."Vote for your favorite team and win an iphone or ipad etc...go to...and then put in your url to your mobile optimized site. People will love to check this out on the smartphone while they're sitting down waiting for the game to start.
So first thing is to set up a simple mobile optimized site (this is just so that when you view the site on your smart phone...it's designed to fit the screen with no horizontal scrolling).
The text for the mobile site will say something like: "Vote for your team and win an ipad or iphone or some related CPA offer"
OK now on the mobile site at the bottom...you're going to have 2 buttons that say something like "Vote for "insert favorite team here" and then another button next to it..."Vote for "insert visiting team"
Both of these links will point to your CPA offer. Use an email submit offer and you will make money this way.