Generally speaking, anyone that will advertise will want to know your daily reach (Impressions).
We've only been running the ad rotation for a couple of days. Here's how many ads we've served per day so far:
6320 2015-03-02 (not a full day)
8892 2015-03-03
8744 2015-03-04 (3 hours left of today, server time)
Note that there are two spots on the page, so maybe you want to halve those numbers if it's page loads you're interested in. But your ad has two chances of being shown per page load, so maybe you don't.
From the little research I've done, $2 per 1000 impressions is common, so if we're having 9000 impressions per day that should cost $18 which is a little under 10 CLAM. Which by a startling coincidence is how much people have been paying per day.
I'll post again in a few days when I have more stats.