SERO Plan no Longer exists for New Customers.It's a highly subsidized plan offered to Sprint Employees Only, but for some reasons the employee email and pass-code were leaked through the internet by its own employee for referral purposes, leading to a revolution. Hundreds of thousands switched to Sprint SERO after the plan showed up on the several deals website and that's how i got one for myself.

At present, Instead of SERO, they have the same plan (Everything Plus Referral Plan) for 59.99 and you need the employee's Email ID and 3 Digit Code to get one for yourself. Here is the email, code and link to the plan. http://www.ecoupons.com/deal/20081115175525726/Sprint-Everything-Plus-Referral-Program-(SERO)