Wow, what about the long term, can images become a problem?

I would think so. Who is paying to store them once the content referencing them is long forgotten, and the users posting them may even be dead? I think all sites (including centralized) are going to eventually face this, once growth slows and they start to look more closely at cost centers.

Short term, the cost of boosting a server is pretty low. Long term, I think it's a problem.