Come in with a well thought out plan and concrete numbers. That is the only way to measure if your successful or not. Changing jobs is always risky no matter where you've been or where you're going.

You need to be passionate about what you're going to be selling even if it's entirely someones else's site or content. The peaks and valleys are extreme. Make sure you want to deal with that before you make the leap. I think for the most part, people in adult are risk takers by nature.