You'd be surprised how easy it is to support web applications, if you work on killing the issues which continue to cause support requests. (BCC had something like 75k trials in 2010. My support load is typically well under an hour a week.)

Maintenance in terms of "Making sure stuff doesn't break" also doesn't have to take a lot of time. January was a bad month for me, and that only took about one hour of firefighting and one hour of (hopefully) preventing the next firefighting.