Hypothetically speaking say you have ... an auto blog commenter XRumer - auto forum poster an auto article submitter auto directory submitter auto social bookmark submitter and say your page is optimized well On-page as well, say you use all those services for a keyword with like 10,000,000 search results how well do you think you would rank after 2 months or so?
Well if you use em all at once and add a few minor mistakes you'll probably be heavy penalized or banned.
There is no way to succeed in competing with a highly competitive term in a very short while. The top ranking terms have age, and this is one thing that you have no way to acquire, even though you may acquire the rest.
Age is just one of the factors. No one except domainer's makes a big issue of it and it's effect on seo is probably overrated.
Age past 3 months will get yah out of the sandbox. Past that, if you can hold your ranking for 2-3 years your pretty secure just doing minimal continued link building. IMO.