In reply to you and smountcastle, here is the text verbatim: If you survive the five-month program, you’ll be offered a position on LivingSocial’s elite engineering team (18-month commitment required).
I read this as, if you TAKE the position on the elite engineering team after the five-month period, the contract is for 18-months. I don't think it is necessarily tied to the 5-month learning period.