In my previous post about Performancing Ads I told there was an ad exchange system where your ad will be shown in other blogs as long as you have credits.I also mentioned that they have not clearly shown how you earn the credits, but John Chow has contacted them and he has revealed the Performancing Ads credit earning methods in his blog. There are two ways to earn credits and more popular your blog is more chances of you earning credits. So not only are you making money from the bids made on your spots but you are getting some free advertising for the credits earned from selling those spots.The two ways are ,
Selling ad spots in your site
you will earn 100 times the amount of credits when a advertiser bids for your spot.for example if he bids for 10$ you will get 10 x 100 , 1000 credits.
Showing other exchange ads
This is kind of similar to Entrecard , when someones ad is shown in your widget there credits are transferred to your account.
All new publishers get 25,000 credits free when they sign up for Performanig ads and if you havent done so now is good time to sign up for Performancing ads 
I’m also thinking of advertising with them with the free credits.
i have signed up for performancing ads a few days ago, but i don’t udnerstand about the pricing or something like that.., thanks for your informations. it’s so helpful for a lazy person like me
Thanks for all the details. I think I might join after reading your post.