Let me post our experiences.
In 2006, we started with one membersite that only had image sets that we bought from Ounique. We sold memberships at a $19.95 monthly price point. Members would only stay 1-2 weeks and then cancel their recurring membership.
Whereas vs. this site we had a video membersite with no image sets. Videos only. We used the same membership price point.
Members to the site with videos stayed much longer. Rather than 1-2 weeks, they stayed 1-2 months and then more.

Keep in mind though, any site you have, it needs to be updated consistently with frequent updates or you lose the members interest.

Videos will always sell more within your members directory. With images the member has to use their imagination. With videos, your giving the customer the imagination thus they enjoy it more.

We have videos coming out of our ears that we have produced, have a license for, or we have bought via content brokers. We update our membersites weekly with 10-12 full videos (scenes) per week. Our members love this and they stay much longer.

The way we update is:
5 image sets on Tuesday
10+ videos on Thursday

We have found this to work out the best.

Now let me ask you this... with xxxcontentdirect.com, they sell DVD content. Whereas Maxpixels sells dvd scenes only. Why did you make this decision? I am just curious. We buy both. Ultimately, our members like the scattered scenes when we update. Scattered scenes meaning, per se one scene from Boys Club the dvd, one scene from us, one scene from another dvd, so on and so forth.

Another thing we have found out to work well is we are now providing the members with a monthly release schedule. They can view 20 second trailers of upcoming videos that will be added in the site. And we have found this to aid in our recurring memberships.

Just some thoughts I'd share with you.