I have a site that gets between 250-300K hits per month, 4% return visitors.

Can I make any money off of ads? Very rough estimate is fine -I just hear some promises from the ad companies and I wonder if its going to amount to nothing. Thanks. Do you need to know more information from me?

what kind of site is it? Any URL?

You might find some takers in here if the visitors would be interested in buying hosting ... me for one

could you post your URL?

I am a partner with mycool.com, we get over a million impressions per month yet only make about $100/mo from advertising revenue. I would suggest researching other means of creating revenue from a website.