I’ve made 3000 friends via blogcatalog. I visited their blogs and i discussed topics with them. I’ve received over 500 visitors from blogcatalog. That’s not much but these are blogger that can potentially become my readers. They can subscribe to my RSS, click my affiliate links, and comment on my site. All of these things make them valuable guests to my blog. Entrecard brings in some good traffic, but i’ve found that they don’t stay as long. This is probably cause they just want to drop their card on my site so they can get points.
When monetizing your blog, the number of unique visitors is important but it’s second place to page views. The more page views you get, the more likely they will click through. Visitors from blogcatalog are more valuable then people from entrecard.