I've never heard of the SE's downrating .us (although given the level of my knowledge of SE's, that doesn't mean they don't). I think there just aren't very many of them to find. Since Americans are used to seeing .com, that's what they're likely to type into their browser if they can't specifically remember the URL - unless, say, they know the site they're looking for is a .org, .edu, or .gov. So those who want memorable URLs tend to go for .com.

When I started my main site 5 years ago, the .com I wanted wasn't available so I got creative and worked the main keyword into a short phrase that ends in "us" (as in you and me), and built the .us into the name that way. It's a niche site, the phrase is niche-related, I use it in a logo at the top of every page, and anyone who's at all interested in the topic recognizes it and never forgets my URL - as long as they remember to put in the "." ;-)

I can't claim to be #1 in the SERPS, but I do usually come up within the top 20 in a search for the keyword I wanted, and most of the pages ahead of me are forum and blog posts. Not too bad, I think, considering my traffic is mostly organic (from other niche sites) and I don't do much SEO. BTW - I've never seen that "taken" .com anywhere in the SERPS.

So I've kind of become a "cheerleader" for .us (hence this rather long post!). The memorability problem is a problem, because most everyday surfers just aren't used to seeing it - or typing it. But I don't think it negatively affects the SE's per se.

[edited by: Beagle at 6:06 pm (utc) on Aug. 8, 2006]