Hand off marketing of a side business to free up time for other ventures?

I sell a niche product to help guitarists prevent finger pain. I've built and launched the site myself, its entirely automated, and I've been getting by running an Adwords campaign which just about cancels out any profits.

I know the business is capable of doing better, but I have moved on to building other projects and don't really want to spend the time marketing this site. Is there any way to reliably hand off the marketing of the site to another party, or is this a scenario where it will really only do better if I invest more of my time personally in it?