This is an interesting idea, as it weeds out clients who are banking on you doing some free work. Still, the "free bug support" idea is a really powerful selli

This is an interesting idea, as it weeds out clients who are banking on you doing some free work. Still, the "free bug support" idea is a really powerful selling point, as it show confidence. Perhaps offer 2 or 3-months of "free bug fixes" with a flexible ending date so you can't ride out the clock. After which, @ashearer's suggestion could kick in.