Psyringe: onlive's
Terms and Conditions (which are hidden pretty well on the page) specifically state "Limit one redemption per household.". You can of course have as many accounts per household as you like, they'd appreciate that as you have to buy a separate playpass and hardware for each account. But if several accounts are owned by the same household, then only one of these accounts can redeem the 1$ game offer.
Note that onlive has several other peculiarities that you may or may not agree with. (Problems with internet connection mean you can't play any games or the games are stuttering, mobility is limited because you have to carry hardware around, you don't own the games you purchase so they can be taken away from you anytime, you totally depend on onlive#s servers to be running for everything, etc.)
Right, my advise is to treat it like steam, don't buy anything that's not really cheap. Or use the play passes and just use it as a video game jukebox account.
If I wasn't getting most of my PS3 games from blockbuster, I'd probably be subscribing to onLive for a play pass.