It depends on the quality of the content.
If you have good girls like these.
Not a lot, if you have poor quality then you have to go the numbers game. Porn, sex, masturbating is addictive. It releases a endorphine into the brain that enduces a good feeling.
Update with 2-3 sets a day that the member wants to come back tomorrow to see then you have them hooked. If you can't pick, shoot or find that level of content then you need to hit the numbers game and supply him with as much as you can to keep him interested. But he will eventually move on.
Magazine and video consumers have been buying/renting the same products for years. some have EVERY video or magazine in the series. Only reason they don't do that on a website is the supply of product. You have to be able to recognise what the buyer wants to hook him.