Wallpaper Downloads

I want to get your opinion on this: What if we required registration once again to download full-sized wallpapers on our site?

Here are my thoughts:

Pros:
-- We would instantly and dramatically increase registration rates
-- Even though a % of registered members would just download wallpapers and leave, it's certain that a % will stay and become active. Some of our best members now only registered because we used to require it for wallpaper downloads
-- Comments on wallpapers would probably increase since some of those registered members would stay

Cons:
-- Some visitors who have no interest in registering wouldn't bother to and would just leave
-- Wallpaper artists might not like this restriction for when they want to link someone to their wallpaper

Am I missing anything else?

The scientist in me wants to do an experiment for a few days to see whether my pros and cons are accurate.

End