Robert Scoble explains the significance of Weblogs.com.
Weblogs.com is an important (and often ignored) piece of blog infrastructure. It’s a ping server. When I post on my blog, it pings weblogs.com and tells it ‘something was just published.’ This lets search engines like Google/MSN/Yahoo visit. It also lets a whole raft of services be built on top of it. Most of the Blog Search engines watch this server for pings.
Source of post: B.L. Ochman’s weblog