As said already it really depends on the niche...
With 3D Toons Photos seem to be enough to keep the surfers satisfied, most sites that do 'have' videos are merely short (very short) clips, or loops, and a very small handful have either bought/leased the rights to the 4 full length 3D Toon movies or "found" them and put them on their sites
I have about 80 or so video clips ranging from 1 min - 3 mins, and IF I can help it I'll NOT be making any more any time soon, the shit just takes WAY too long, and well, to be blunt, most companies don't want to pay what my time would be worth to make more (or longer) videos.
Perfect example: one GOOD 3 min video clip takes about 2 weeks from setup to final render, what would most buyers want to pay for that? (about $10 - $30 tops), soooo I'm worth $5 - $15.00 per week???
All joking aside, depending on the niche (such as toons) pictures only CAN and DO still work. (BUT you better have a gooood archive of content and lots of updates!)
-Loki-