[ATT-Half]

so what exacly is sprint Sero

I just sign up for sprint with there simply everything plan $99 paid $129 for my HTC pro no rebates to deal with.
I would like to think i got a great deal on it.

Now Im reading about this sprint Sero plus referral program don't understand much google that term sprint Sero plus referral program i get alot of info about it been dead everything july 07 2008 and something about an extra $10 off your bill

what the difference bettewn the simply everything plan and simply everything plus
and if any how can i upgrade i been 6 days since i got my phone