The way I think about online marketing is there are flows of users, and the job of the online marketer is to tap into these flows.
You need to identify flows you can tap into. An example is using hashtags on Twitter. Rather than just sending the tweet to your followers, you’re tapping into an existing flow. This is especially important when starting out, when you have no followers.
Another example is posting on a forum. You’re tapping into another flow there.
And again, posting on a blog can tap into a flow through Google search.
The important thing is to maximise the quantity and quality of flows that you’re tapping into.