Greg Wilson once commented that the subversive way to get scientists to use source control was not to pitch it as a code history tool, but rather as a nifty way to sync up code between their work machines, home machines, etc. He said he had a lot more traction with that than trying to lecture them about having code history.
I'm guessing Dropbox has introduced many a scientist to the wonders of code history/portability. I was pretty reluctant to move to Git when Dropbox worked fine.
That's probably good for arguing about good backup practices too. In the department I worked in it was common for grad students to have months of code written on their laptop that was not duplicated anywhere else. The problem is that these students were working independently and didn't really have a need to transfer the code anywhere else.
