i think .co can take over
I was just reviewing this threadm and don't believe I responded earlier with my personal answer to your question @DigitalRoar. Barring something completely unknown to us now, I don't see any extension reaching .com in first place for foreseeable future.
I feel less sure about the possibility that a different TLD will reach place 2 or 3. Org seemed solid, but of course recently developments leave questions in some minds. Net has been fairly constant but not growing and dropping slightly, it seems.
I think it is possible with aggressive and inspired leadership and marketing a generic country code, or possibly a new extension, might sometime reach position 2 or 3. To do so they need to have it priced to compete (similar to .com renewal wise), build trust in how it is managed and long term, build consumer acceptance for it with marketing and promotion, and to some degree .net/.org go down with problems. All of those things happening is probably unlikely.
Most of the new extensions could never move to 2 or 3 because they are too specialized. A few like .xyz are general purpose, but don't seem poised to get anywhere near position two. A short, general, non-English word TLD would have certain advantages where most business and Internet growth will be in next decade.
If I had to bet on which TLD might possibly reach position 3 in a decade it would be, simply my personal opinion, probably .co or .io (if latter continues to broaden its use categories). I think the high renewal rates are holding back their broad use to some degree currently, however. It is not that most companies can't afford $35 per year, but it is rather the very early single person startups of a young person in or just out of school even that much seems significant. And of course to domain investors with a 1% sell-through it means that it is a lot.
Since the stats are based on DNS queries - .uk has to be queried first before going deeper, so the number will be slightly higher than .co.uk (because there are also some .uk domains, as well as .ac.uk, .net.uk etc.).
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