I'm known for my ability to generate traffic, and I work behind the scenes on some pretty successful sites to do that. The problem that I see far too often online with other "gurus" is that they seem to focus on talking about getting traffic.
Now that may seem strange, but stick with me for a moment.
If you want traffic you can go out and buy some "guaranteed hits" from any number of vendors. You can get so much traffic that your server literally can't handle the load; but not a single bit of it will be come a subscriber, a lead, or a customer.
It isn't enough to get "traffic". What you want to do is make sure that you are getting real VISITORS to your site and you want visitors that are highly likely to be predisposed to buying from you.
A few hundred of those is far better than ten million "hits" of random traffic.
So, if you truly want to make a killing online, start by defining, in extremely intricate detail who you want for a customer. Once you've done that, actually getting those kinds of people to visit your site, while repelling people you DON'T want, becomes significantly easier.