I have a custom audio service on the site as well which I recommend for people seeking exclusivity and the more traditional commission approach. The prices are still lower than most composers can offer, but they're obviously a good deal higher than what I can offer for the non exclusive library tracks.
I've also considered the buyout approach for the library, and it's something I may eventually include.
I compose all of the music at the moment, but as the business grows I would like to potentially bring in other composers and sound effect artists to offer a wider selection of styles.
That's actually on my to-do list. I want to create a series of shorter "jingles" that can be packaged and sold as bundles in various styles (so you'd have a more orchestral set, an electronic set, etc). It's definitely something I want to have available sooner than later.
I don't have hard numbers but given the popularity of web and mobile game engines, like Unity3D, there are numerous people entering the game development space. Music seems to be one of the most often requested areas and most indie devs either try to make it themselves or buy really crappy music. I figure I can offer them affordable yet high-quality music. I've been talking to a handful of social/mobile studios as well and have some ideas on how I'm going to change the business model to support them.
Yeah, the website could definitely use some improvement. Revenue is trickling in currently, hoping I can contract someone to spruce it up. I've been told HTML5 audio players would make a big difference in loading speed.
I've also considered the buyout approach for the library, and it's something I may eventually include.