There are some people who make a living on Flippa (or "try" to make a living on Flippa) selling templates. Some of them are a lot more prolific than others and I guess the ones who list the most are the ones who've found a way to make the activity profitable.
Here's a rough breakdown:
One of the biggest offenders / most successful (depending on how you look at it) is smartbusiness with 849 listings and even better than him is the (now) banned Sun Shine who listed over 1,000 before he got banned. (That's just in the Sun Shine account. He seems to have had other accounts as well.)
The ones with the most failed listings are the likes of allenjohn, motley and surprise, surprise Latonas (the latter seemingly using Flippa to drive traffic rather than to sell). 50-60 unsold listings seem to be no problem for these folk.