Minimum web traffic for advertising

I was also looking for help gauging my sites value for paid ads.

I have a live lake erie cam based site that has been in the wild for a few years now.
It’s in the top search results when using the core description of the site.
Hits are ramping up slowly.
In 2008, About 1500 unique visitors per month and 4500 total visits per month.
In 2010, About 4000 unique visitors per month and 16,000 total visits per month.

I know this is small apples but can I still make any profit?

I would like to find some paying advertisers.
I went out publicly in the past to people that have business that would fit the sites demographic, I got some nibbles but nothing solid.

let me know if i should post anymore info here to help with my goal.