There's a saying that "advertising abhors a vacuum." In other words, if there's a blank space on a wall, telephone poll, or the back of your eyelids, eventually someone will figure out how to put an advertisement there. With that in mind, Google has rolled out two new features this week intended to help fill the vacuum.

First up, the company continues to try to justify its massive investment in online video. Making money from YouTube videos has proven surprisingly tricky. May viewers are resistant to pre-roll and post-roll video ads. And in-video pop up ads can be even more annoying if not handled properly. One possible solution? Affiliate links.

YouTube is rolling out "click-to-buy" links on some videos allowing you to purchase music featured in a video from Amazon or iTunes. Even if you're not planning to buy the song, the links can help you identify the music playing in the background of some popular videos.

Google is also rolling out a beta of Adsense for Games. Basically, these are ads designed to be integrated with web-based video games. Ads could include video, image, or text ads that will appear within the game.

No word on the AdSense for eyelids thing yet.