Tracking sales, visitors?

[djixas]

Is there any tools for tracking visitors, for example, how can I know if I've boosted lets say for keyword

buy ipod to position #1, in google, how could I know how much of my buyers came from google but not from some link exchange sites or something?

And how much came from yahoo and bought ipod if I am #2 or so.. I hope you got my idea :)

[T0PS3O]

Use Google Analytics.

[cianuro]

I second that. GA is absolutely amazing. The goal tracking (Although sometimes 5 is not enough) is wonderful.

I have to say, in the beginning, I was only using it to track traffic and not visitor behavior. When I started doing that, I found all sorts of interesting things out about my site and network. Then its tweaking time.