Snapnames is a backordering service.
Although the domain may be available for backorder, it does not mean you are able to aquire it. The only time Snapnames will try to aquire a domain is when it drops (expire). If you are looking to backorder an well known or premium domain, I doubt it unless the current registrant forgets to renew their domain (which is very unlikely but happens.)
However, if you are among the many who have backordered the same domain, the you will have to go through a snapnames auction and the highest bidder gets the name.