The best kind of traffic is free traffic, I think we can all agree on that.
There’s just this one little problem: Free traffic isn’t free.
At least, in most cases it isn’t.
If you’ve ever tried to rank for anything but the crummiest of low-traffic keywords in Google, you might have had a frustrating experience. Just optimizing your website certainly won’t get you there (and unless you’re in the top spots, you won’t see hardly any traffic).