I'll try the contrarian view today, just to see..! I wonder if a better question isnt "how often do you verify" your backups?
I manage a couple small businesses, and the reality is I test backups perhaps once a quarter. Losing a quarters worth of information would definitely hurt, but it would be survivable. Why don't I test more often? Time, and experience. I have a limited amount of time each week, and a lot of things to do - that combined with my experience telling me that bad backups are pretty rare, I can extend the risks I take, with an understanding of the dangers.
That's how it is with many small businesses. Even if you have a DBA, do they really need to verify every backup? Even if you do one a week, you potentially have a 7 day gap where you might have the ability to restore to point in time. Is that acceptable?
Why doesn't MS make verification automatic, or include a step in the maintenance plan for restoring a test copy and checking that it's valid?