Timing Chip Purchase

Great question.  I have always wondered this to.  I really can't see an advantage.  Heck, at one race I saw a guy with his own and the timing chip company said their prefered they he used theirs anyways.

Some races will give you a discount if you have your own chip. 

I don't know that there's much of an advantage.

I did the Austin Distance Challenge and you have to have your own chip because that's how they track results across the races. I use the chip in tris if given the chance, only because it's one less thing I have to worry about at check in.

With most of the chips, you can track your races by it. You set up a profile and go view your races/splits at any time without having to go to the individual race results sites.

In the past, generally, when you registered for races the race fees were broken down more and if you had your own chip you could generally avoid the cost of the fee required to "rent a chip" for the race.  From my observations, there are very few races these days that offer a discount if you have the chip.  They will often allow you to use it, but then you just get the "bonus" features of your own database of your times/splits, etc. as Dennis described above.  As races have become more popular, the race fees have become more "flat" for everyone and you pay for the chip regardless of whether you use your own or not.  So, in the past there was an advantage to having your own as, after a few races it could "pay for itself"--but from what I have seen/discussed with some friends on this issue, there really isn't much more than that to it.