What makes entrecard so addictive?

"A dedicated dropper with a hint of addiction..."
I am guessing that Entrecard is a portmanteau of "entrepreneur" and "business card." Though the whole idea of turning us into "click monkeys" to generate traffic to our respective websites and blogs has been done before, what makes Entrecard unique? Entrecard was preceeded by other traffic generating sites such as Traffic G and linkreferral.
Yes, the whole business card idea... so damn simple, we are all asking ourselves, "why didn't I think of that?" To be sure, whenever we ask ourselves that very question, you already know it was a "Post-it note moment." Of course, people are already accustomed to and habituated to handing out business cards. Why not allow them to do this on the web?
Entrecard only includes blog sites. This was another simple, yet key idea which helps Entrecard maintain a sense of community. Basically, though we are still 'click monkeys,' we now are part of somewhat of a social networking site as well!
Entrecard Psychology... okay this deserves more than one bullet point. In one word, it is based on the principle of positive reinforcement. However, it takes this concept to another level. Unlike other sites, where I click on your site, write a review, and move up in the listings so that I will likely get more traffic... Now, I drop my entrecard on your site and you not only know exactly who gave you traffic and an in turn an Entrecard credit (immediate reinforcement), you now feel compelled to return the favor. Do you ever feel guilty when someone drops a card on your site and you haven't completed the circle by dropping back on their respective blog?
The postive reinforcement of Entrecard dropping is two-fold, not only do I get a credit for dropping my card, but additionally there is a pretty good chance that the person will see my card and return the favor thus giving me another credit (intermittent reinforcement). Additionally, not only are we reinforced by getting Entrecard credits, but we also increase website traffic to our respective blogs.
So now what we have is basically a token-economy. Hm, now we are talking about a system used in behavior modification in which tokens are accumulated and spent on a reinforcer (ads to get more traffic or selling for $$$). Now, this leaves us with a social networking/traffic generating site based on the principles of operant conditioning.
Summary... Entrecard employs the principle of positive reinforcement (which is actually stronger than negative reinforcement), integrates the intermittent positive reinforcement of people returning EC drops, and uses a token-economy to fuel this card dropping behavior.
How BIG will Entrecard get? For now, it's difficult to predict, but given that virtually anyone can create a blog tomorrow and instantly start to generate the type of daily traffic that once took someone with reasonable blogging accumen months to generate, the future's looking pretty bright for the folks over at Entrecard.

