Why don't clips sites sell credits?
 

Like instead of charging the customer's credit card each time they make a purchase, they'd purchase credits in say blocks of 20 or so to spend on the site. Seems to me it would definitely encourage more spending. Casinos figured this out a long time ago. They use casino chips because psychologically people are more willing to spend them than the actual cash.

http://static.guim.co.uk/sys-images/...and-Du-010.jpg

I ask a site once and they said because their making great money without doing that.

I think in general, on sites where I'd expect multiple smaller transactions from someone, I'd offer a credit purchase such that they'd save money when using that credit, which in reality might be half of the savings on processing all the smaller payments. Both for the reason you said (they spend credits easier than money) and of course the potential that they don't spend some of their credits at all.

Then you could even offer monthly memberships where they could get an even better deal - either get daily, weekly or monthly credits for a monthly fee. That's basically how stock photo sites work.

I'm going to hazard a guess that Clips4Sale and other major clip sites know what they are doing with their business model. But anyone can set up their own VOD system that runs on credits or tokens if they wish. PhantomFlicks.com has one such script you can use on your own site with any biller or you can create your own.

Some do, some don't.

We use a token based system for www.DirtyDvod.com and it works well.
+1 for Phantomflicks