IPv4 addresses is running out. One factor is because VPS are going cheap nowadays. Do you know how many IPv4 addresses does Digital Ocean currently use?
http://bgp.he.net/search?search%5Bsearch%5D=digital+ocean returns a list of Digital Ocean's ASes. An AS is a top-level chunk of the network, so you may assume that Digital Ocean operates seven technically independent networks with a total of about half a million IPv4 addresses.
By way of comparison: Before the strict IPv4 rationing regimes came into force, v4 addresses were being allocated at rate of about half a million per day.
By way of comparison: Before the strict IPv4 rationing regimes came into force, v4 addresses were being allocated at rate of about half a million per day.