evoke,
Just to follow on from the points made by CGorman.
For advertising purposes, what is important is
- Page Impressions Per Month. This is the number of page impressions (as opposed to hits) for your website per month. Most hosting packages should give you an option to view this info and should also filter out traffic from GoogleBots/spiders etc..
- Number of Unique Users. Obviously, if you only have a few users generating a large number of Page Impressions, this will be of no use to potential advertisers. What is important is the extent of the end audience.
As CGorman says also, rates that will be paid depend on your audience and how they will fit with advertisers (e.g. myhome.ie is a good fit for mortgage providers etc..)
You can also go the AdSense route - I have no experience of this mysef so can't comment on how much you are likely to make..
dockingtrade - you can get paid for banner impressions but I think that most advertisers will meausre clickthroughs to see how effective campaigns are..