I was always amazed at employers willing to gamble on new employees who have had multiple jobs over a short period of time as I would frown upon this.
It is a hard market to get good people with experience out there - cheap at least.
I didn't know the sales people received accounts left by others and is actually a decent bonus if you stick around long enough.
They have to be moved on to others, as they need service and support over time too and they often grow and need more licenses or implementations in new regions. It can be massive for a sales person.