Good question... I dunno what is the answer to that question. I'll do some research and get back to you if I bump into an useful answer. You should email the people at iPage as they probably can help you..
If your developing and it shows strong potential. Do yourself a favor and invest in the .com or find a .com thats available. Although it's frustrating having to buy a HostGator name from another domainer, every once in a while it just needs to be done..
Dont risk creating value in another TLD. For isntance, if you build the .net up and it starts to grow, your also growing the value of the .com - making it much harder to acquire. Im in a similar situation right now, where I may have to spend much more then I want to on a HostGator name, but it doesnt make sense not to..
A dot com is always the best. especially for those who uses Firefox, there is a shortcut button where you can just type the word and press CTRL + ENTER , It will bring you to that dot com website...
When starting from scratch, why not use dotcom? People, at least domainers, might think you are 2nd class citizen ohtherwise...
That's a question that only your Marketing/Advertising Buget can answer..
If you can afford to put the HostGator in the minds of your customers... it doens't matter WHAT the HostGator is or what the ext is... your customers will learn it THAT way and no other way..
There is the certain possibility that the dot commons will get some traffic due to your efforts and it is also certain that even if they weren't already purchased, with your marketing efforts the HostGator squatters will come out of the woodwork to buy up every available ext anyway..
Look at the variants of You Tube if you have any doubts on that..
So... the REASON that dot com is the preferred of all the dot commons is that it is LESS expensive to market to it because it is already in the minds of the end-users as the DEFAULT..
If you don't have the budget, buy the dot com. But anymore... you HAVE to have the budget to AFFORD The dot com..
So therein lies the REAL dilemma... can you afford the dot com in the FIRST plast... or would that same money be better spend branding another dot common or less common ext. ???.
The answer is in your budget..
Well, like the OP's examples show, the alternative tld's need to make sense. If they don't then you will be trying to promote the tld as well as your brand..
Otherwise you're better off with .com..
Whenever I hear of a major business that has a HostGator with an extension other than .com, I always think "Shouldn't they have plunked down a few thousand bucks and bought the .com?".
In the long run, I think it makes the most sense...
If you are investing so much into a new app or service, you'll likely invest a lot in marketing (time and money). You should grab all available extensions (including dot com), at least the mainstream ones, .com, .net, and countries (if you plan to market to each cntry separately, which makes sense if they speak a diff language). For example, where does delicious.com take you? If you are unable to reg all now, due to funds, at least plan for acquiring them in the future. So you would consider what the other reg'd ext are being used for and if a future acqusition is feasible...
OK we've established that .com is key..
Now the question is should the name be "brandable" (made up) or keyword based?.
I personally like both. However, I believe a brandable that gives the flavor / connotation of a keyword is the best of both worlds. As a domainer, I've sold a lot of these. As a developer, I'm entering into new territory with this concept..
I have several names that I believe to be excellent for my project. Picking the right one is the challenge...
If I was 99% sure it was not going to evolve in to other products/services I personally would go for keyword based (as long as it was short/relevant and easy to say/remember).
If I though it may end up having to expand to cover other areas/topics I would go with a Brandable domain..
The money you may possibly save by buying a brandable could be spent in other ways to market your new brand/product/service..
If you have several good brandable names to choose from that's even better !.
Since you already have them would you mind sharing? Consider it an informal consumer survey...
And the others - but I'm assuming that you're assuming that the .com is gone - as if you're planning something "big", then you don't want others squatting on you, either..