Google has been updating its indexing systems to treat some TLDs differently than in the past. Some country-code TLDs are being treated as generic TLDs.
The list, which may still change more over time, of generic country code TLDs is as follows: .ad, .as, .bz, .cc, .cd, .co, .dj, .fm, .gg, .io, .la, .me, .ms, .nu, .sc, .sr, .su, .tv, .tk and .ws.
Google's Pierre Far shared the news in a Google+ post (via Search Engine Roundtable).
Expanded list of ccTLDs treated as Generic ccTLDs
Over the past few months, we've been updating our indexing systems to treat certain country country-code TLDs as generic TLDs; that is, even though the top-level domain has a country code, we would treat it, by default, as not targeting a specific country. Now that all the pieces are in place, we also updated our Help Center article listing the TLDs we treat as gTLDs:
The latest addition includes the quite-popular (and personal favorite 🙂 ) .io.
Geotargetable domains - Webmaster Tools Help
Generic top-level domains (gTLDs) don't target specific countries. If your site has a generic top-level domain, such as .com, .org, or any of the domains listed below, and targets users in a particula...
Google's Matt Cutts recently did a Webmaster Help video discussing location and ccTLDs. If you're reading this article, you might find it helpful. You can get the gist of it in text if you click the link, in case you don't feel like sitting through the two-and-a-half-minute video.