I believe that when a new map comes on and comm vote happens etc, when everyone spawns it comes out of tickets. I'm suggesting that that first spawn doesn't come out of tickets, cause it's ridiculous when playing on a full server and your team just chewed out 27 tickets.
On a different thread, Trickster had an interesting idea that fixed a lot of the problems of tickets: I think it would really give games three distinct stages. The beginning where suiciding and going "all-out" is encouraged, the middle when tickets emerge and lives matter and finally sudden death with its unique strategy and enormous risks. So the game goes from least strategic to most strategic.
I know they used to. This is also why you can't spawn on a team with 0 tickets, since your first spawn uses one. I also recall actually seeing the tickets drop as people spawned at the start of the round. Unless this has changed in a recent version. Grants suggestion doesn't really seem like it would help anything anyways.