It depends of the campaign and what the blockchain project uses ( Ethereum, Neo, Qtum etc.) If company makes its own blockchain like Hdac for expamle the distrubition can start within even year end of the ICO.
As for the HDAC project, of course, no one could have imagined that eventually they would drag out their project for so long. Many investors have received their coins only recently, and bounty hunters in general have received nothing so far. Very bad for their reputation