When you paste a site URL into Feedstand to add a feed, there used to be a short wait while it visited the site, scanned the page, and figured out which feed was the right one. That wait is gone for sites that were already seen. The feed shows up right away.

Given that Feedstand has a large collection of feeds already, there's a good chance the site you're pasting is one of them. When it is, the feeds come back straight from what's stored, no visit to the site needed.