You have someone working your table on the ground. They sell snacks, shine shoes, and watch your tip jar. They split the take with the parachuter. Also, the parachuter has a sign there, so people know which parachuter they're tipping. There tends to be several in the sky at once, since they're dropped from the same plane.
The parachuters may do things like dress as celebrities, lipsync song-and-dance routines (to a boombox they carry, which simulcasts with the boombox at their table), or do tricks in the air, such as cooking or tandem-parachuting and trading clothes with the partner.
It was pretty exciting to watch!