When I first saw cards like this on blogs, I was puzzled. What the hell were those things ??
When it first launched Entrecard has a very original concept, and still does.
Bascally you go out and hand out a virtual business card to help with the promotion of your blog. No money involved. All credits are virtual! (However there are people selling EC credits on eBay for real money).
How it works
You sign up (one blog one email) and you have an initial price of 2 credits for advertisers to put their cards on your blog. The price goes up as you collect more credits. You can go to other sites and click on "Drop" to earn one credit. The website owner will see your card that you drop in their Entrecard admin panel. The same goes to you. You can see all the cards other people have dropped in your inbox.
Advantages
The cool thing is once you sign up and become a regular card dropper, you'll see a spike in traffic. Many say Entrecard traffic is useless and junk traffic because Entrecard visitors aren’t very likely to hang around after dropping their card.
However, there are some who stay around and actually read your content if you can have something that catches their eye.
Another positive is that you can even get your ads on one a popular blogs such as problogger.net or johnchow.com without paying a single cent. Just need lots of credits that's all.
Joel Comm that Adsense ebook seller has just become a member Entrecard and you can advertise on his site too.
So far my experience using Entrecard has been positive. I have to say that established blogs like 5xmom, LiewCF and HongKiat would not benefit at all from this program. Only newbie bloggers like us will benefit more in the instant traffic and potential to hook one or two loyal reader. Just make sure you have some good content or interesting post.