After Valleywag called out Circle, a contact list-bombing social network no one asked for, the company's CEO apologized via bloggy mea culpa, and pledged to be less annoying. Good!

Says Circle creator Evan Reas:

Over the last few months, we have been constantly experimenting with ways to share the application with friends and build your local network. We know that the app is much more useful when your local network is bigger, just like LinkedIn or Facebook. It can be a tough balance to strike to allow people to share the app with their social network but making sure it isn't too much. We do want you to be able to share the app with your friends, but not bombard them with invites so after experimentation we have settled on sending each person a maximum of only 3 total invites on facebook and 2 invites through SMS. If a user receives more than that, we won't allow them to go through.

Emphasis added. Well done.