Entrecard is a free blogging network that brings real visitors to your blog. You can join in their network and you can earn Entrecard credits which allows you to display an ad of your blog on other blog sites within their Network. You can earn EC credits by dropping on other's EC widget.. Hope I made it clear
It is an artificial method of generating traffic and is a type of traffic exchange program but since the traffic is not organic, it does not help to monetize it well. Also, you need to spend as much time on browsing other blogs to get the visitors in return. It is good to employ their services if you are starting out new and intend to just get traffic stats up, for your blog. Regards, RightMan
It's for traffic generation. To earn credits, you need to visit drop entrecards on their blog. Once you earn enough credits, you can buy ad space on other people's sites.
Just wanted to add something! I am a member of entrecard for more than 3 months and the best thing of entrecard is the Marketplace. You can sell links or design a logo and earn credits then use them for buying a SEO service or a an e-book.
Entrecard offers a dynamic advertiser experience, create and manage multiple campaigns on the fly and track your results in realtime. Choose between CPC for products and services, and CPM for brand building.