I worked in animated TV commercials for a lot of years. The good thing about commercials was that they had relatively high budgets (at least compared to TV series) and there was a variety of designs and technical challenges.
Eventually, though, I reached a limit. One of the main reasons was dealing with people from advertising agencies and their clients. Now, you can experience the wonders of ad agency folks without having to work nights and weekends to give them what they want. Check out this website, which claims to be verbatim comments. Based on my experience, I'd say that was an accurate statement.