Some time i think that why few people have more traffic even if they have poor PR and backlinks. I also wonder why sometime few site do more business then the site which are highly promoted and even ranked. YES linking and blogs etc help your site in better visibility, but if your site contents and struture is not in proper shape, it can be ranked and will not have good traffic.

Other main thing i this the choice of keyword. Some time we think that normal keyword which comes in our mind have more traffic but on search engine it is most of the time different what we think. Like "Copper cabel" have less hits then many other similer keyword.

Second thng is important is, choose targeted keyword/key phrase rather choosing TOP level keyword which some time generate non required traffic. Like if your are providing service in JAPAN only then choosing global keyword is more expessive and it also take great efforts to get ranked. And generate less business for you.