The problem with those extensions is their limited scope. You just can't put any keyword to the left of .guru or .sexy, .link or .whatever. These TLDs are gadgets to me, I can't use them for my real-world business, which is a serious business.
On the other hand a .com or ccTLD is versatile. It can be used for anything.
Since the supply of meaningful keywords is limited, the growth prospects are capped from the beginning.
And accordingly the demand (if there is one) will be tiny as well. There isn't going to be enough volume.
It's already hard enough to turn a profit on .com. The few opportunities in this game are for the registries, not the ordinary domainers.
such as computer.guru, music.guru, merchant.guru, marketing.guru etc.:wave:
To take an example, computer.guru was actually bought by this guy:
http://domainincite.com/15711-meet-the-first-new-gtld-domainer
The guy apparently spent $30,000 on .guru domains. Ouch.
I almost feel bad for him. People like him have gambled on the second coming of .com, they all got burnt, always, for a reason.
I mean, it's okay to speculate, even to buy stuff that is
worthless but do you really need to buy hundreds or thousands of domains when you know you are only going to sell a couple at best... the few sales are unlikely to offset the losses and renewal costs.