Hi,
A successful site is one that ranks high enough for its chosen search
terms that it gets sufficient visitors to achieve the objective that you
had in setting up the site in the first place.
silvermoon
I think a successfull rank on the SE's is one that actually pull sin traffic. There is no point in having a top rank if your not getting that keywords searched enough or you do get into the top of a popular keyword only to find your title and description suck enough to not attract any clicks.
Web Site Idea, Is it in demand, is it something people need.
The keywords you choose to target, how many times are they searched a month?
How can you get the top rank on these searched keywords.
Most importantly, content of your web site. Is it better than everyone else. Will people bookmark and telll their friends.
How much of a profit can you make after doing all of the above, and is is worth your time.
The site appearing at the top for its choosen keywords can be considered as a good ranking website. Succesful site is one which has quality content, proper relative keywords, high PR and sufficient visitors.