Let me start by saying “I don’t recommend spending money on new gTLDs or starting a business using new gTLDs !”.
Most of the new gTLDs are too long to type like .company, .property, .business and you wouldn’t really want an extension to increase the typing effort for an average internet user.
Another thing. New gTLDs are not intuitive/accustomed to. It may take a long time for an average internet user to accept and use new gTLDs. I’ll say it again. If they are ever to be common sense for the average internet user it will be a LONG time.
When you create a site on a URL like “myname.mylonguselesstld” trying to form a brand by combining the two parts (I mean the name and the extension) it will be really hard to tell people the URL of your site/business and stop them from typing mynamemylonguselesstld.com/net/org into their browser’s address bar. You will be losing “a lot” of traffic to your competition. In that perspective, new gTLDs would not be attractive to any serious company/project. These days, where new gTLDs are still unknown to many people, even if you printed “myname.mylonguselesstld” to your business card people might end up thinking that it isn’t a website address but a Skype ID 🙂
For example, bendthetoys.com (just a random name) will still easily sit into the customer’s mind if he is not an avid user of the Internet, than using something like bendthetoys.store as many people still do not know about these gTLDs, and might even ask – how do I end this? with a .com after .store? Consumers are slow adapters to changes not just online but also offline (Quote from wwwblog)
Prestige: Most of the people expect a business to have com/net/org URL for their website otherwise they are likely not to be taken seriously. Truth hurts.
Registration fees: Most of them are more expensive to register than a .com/net/org domain.
Aftermarket: I have been following the aftermarket activities on these new gTLDs and I can say they are not doing well. Domainers are not attracted to them and they are not treated as valuable digital assets, not at all. Serious domainers are still after the big ones like com/net/org and sometimes TV. Check this out for my thoughts on TV domains (which have been around for many years and earned their place).
As I said in my post in the link above, IMO, the new gTLDs are just there to make more money for ICANN and registrars.
Registrars: Not all the domain name registrars are offering all the new gTLDs and there are limited options for users, which hurts the trust in these new gTLDs.
Operators: Who are running these new gTLDs? Are they trustable? Do we know for sure that they will keep them up & running even if they start losing money?
Area of Interest (Applicability): Most of the new gTLDs are targeted for a specific area/business. They cannot be easily used by different/various businesses. Could you do an eBook business using .photography extension? You got the point.
Some people say some new gTLDs may have search engine advantage since they are valuable keywords on their own in some areas. That is totally wrong. They will not be getting any special treatment from the big G. Check this out: Matt Cutts – Google+.
That is all for now. I could come up with more, but I am really tired now 🙂
Hope this helps.