I Read that TLDs don't affect Serps at all, but I rarely every see .US domains ranking well for anything... Can someone provide some insight on .us and serps? Besides Delicious, anyone know any good .us domains that rank well for some keywords?
TLDs can affect SERPs, in as much as they reflect geo-targeting. For example, a co.uk domain will rank differently than a .com if you are in the UK. A .us should perform the same as a .com, though.
I have done experiments before, same contents on the .com and .info, the .com has more traffic and higher PR
It doesn't matter if you've done experiments before. Of course, the .com would have more traffic if the .info was copying the content. Now, you would be screwed if both sites were to be penalized.
It's also worth noting that .coms are perceived to perform better not just because they're more widely used, but also because they tend to be older and have better link profiles - two major factors in Google rankings. As the guys agree, the ONLY difference that a TLD makes is the geotargeting in local versions of Google.