Yes, if you look at http://gs.statcounter.com/ http://gs.statcounter.com/ and select individual countries you can see that Opera is strong in Eastern Europe and

Yes, if you look at http://gs.statcounter.com/ http://gs.statcounter.com/ and select individual countries you can see that Opera is strong in Eastern Europe and parts of Asia. There are historical reasons for that (just my opinion, see bellow) and also the fact that Opera had/has Turbo - which really helps on slow connections (mobile). So if you run US-focused site, there isn't really reason to care about Opera, and test for it. Blocking it (or any other browser) is bad though. The "historical reasons": Opera was by any means the best (serious) browser out there, but it was paid. People in these countries weren't paying for software anyway, because their income was well bellow western standards while prices were same, and as a bonus, there was no one who would care. So while someone on the west would rather use something free (like IE), people in (for example) Ukraine picked the best. That's why first decent browser (Firefox) took over the west so fast.