They are used for GA
planes as well. During my time at Daytona Beach Jet Center we had a Follow Me cart to be used for various occassions. One such was when my supervisor sent me out to meet an Army Huey at 'point', the farthest we could go off the apron, and bring him in to a parking spot.
It's been a long time ago, but if I remember right it was mainly used for corporate jets coming in, DoD aircraft, and during high density parking times, like the week preceding the races here at DAB