[Taptitude Developer Here] I've heard of much higher eCPM (and much lower) on pubCenter.

It's a factor of many things including click through, rotation frequency, ad category, user demographics, etc.

I don't have experience with other platforms, but I've heard that pubCenter is one of the better ad networks.

It can be very low, depending on which impressions you're buying. Not all impressions are equal, and more importantly, some impressions are worth more to some advertisers than others. The more finely-targeted your ads are, the higher your CPM will be. Note that "targeting" can mean serving ads to a narrow audience segment on a large network, or it can mean running indiscriminate ads on a small site with a very specific audience, or anywhere in between. "Windows Phone 7 users" is a very specific audience, but I don't think it's an incredibly valuable one compared to the broader segment of "mobile gamers," so they won't get great $CPM unless advertisers can segment their users.

Its not really. We're still figuring things out, nowhere near their traffic, but similar eCPM. (Android/AdMob)

http://imgur.com/9pT9V

Comparatively we get $5-10 eCPMs from AdSense on websites.

Pubcenter / Microsoft's ad exchange performs (eCPM and fill rate) better than anyone else out there. I know because I work with 20+ networks. As mentioned in other parts of the thread it's probably because there is more demand and less supply.

Seems really high to me. I don't have any experience with mobile ads, but I used to run some pretty high traffic websites and we worked hard to get $0.50 across all of our traffic. First tier serves always got more, but it dropped off quickly.

It depends a lot on who your users are, what ads you show them, how they're positioned. It seems like a decent number for a bunch of mini-games, but it's really hard to generalize.

I created a WP7 app that utilizes Microsoft Pubcenter. My eCPM fluctuates between $0.90 and $1.00. When I first released the app, about a year ago, my eCPM was much lower (around $0.25).

Anecdotally, I've heard or read that around $1 is decent but I don't have any data to back that myself = /

That's only .1 cents per view.