How do you ( successful programmers ) track your site traffic?

I’m finally at a place after developing countless losing business
websites of finally getting some traffic.
I am aware of the Request object and the fields describing where the
request came from and where others go.
I can’t imagine that you guys are actually save a record for each
‘hit’ onto or off of your site.
Are there any mainstream strategies in use where one can provide
credible information to advertisers.
I am most grateful for your experience.
David

Google Analytics?