Over on http://www.bedandbreakfasts.co.uk we get about 6K visitors a day, and revenues approximately 1,000 GBP: Giving a value to each visitor at GBP 0.1667 – visitors on this site have a high commercial value because they are looking for Bed and Breakfast, and likely have their credit-cards out, and ready for action.
Lower values are likely on “information only” sites that rely on adsense and other click-based revenue. http://mdtravelhealth.com used to get about 30K visitors a month and make 100 USD. This gives a per/user value of 0.0033 – many multiples lower than the high-value site.
If you want to look for your site’s value: I’d reckon it’s somewhere between these two – depending on why the visitor came to your site.