Forum Moderators: phranque
There was such a case not too long ago, with over 200 sites hosted, using a shopping cart, and using the provider to process credit card orders. Many of the people involved were at a loss to know what to do, since their sites had also been designed through the service, and their domain names also registered by that site operator.
That's unusual, but moving a site wouldn't hurt if the timing was right with the move and main pages stayed functional, even if it took a little bit to get the ordering back to normal with another provider.
It isn't easy to re-do everything in a hurry, but it's a good idea to have everything set up with enough mobility to be able to make a change as quickly as possible if necessary.