People on smart phones spend money, almost nothing is free, and they all purchased with a credit card. Zero competition in the global scale of things. And finally, another set-it and forget-it income stream.
If you don't want to re-encode your stuff, just promote someone else. One way or another, if you aren't monetizing Mobile traffic, even before your own site is up, you're leaving money on the table.
Hit up
TopBucks and give'em a shot on the REVSHARE program... a few minutes of your time is extra money in your bank.
Can't beat the time vs income ratio, I promise you that.