Due to the dependency on the provider a change of  contractor or switching back to in-house operation means that new cloud  services have to be developed matching the architecture of the new vendor. Also  the customer has to wait until the contract expires (BEISPIEL für wie lang). This expires. This  procedure can be very time consuming and costly and can lead to a  lock-in-effect. This means that a switch of the provider gets uneconomical due  to due to the high switch costs. 

Also the possibility that the provider could go broke