Out of all those extensions you mentioned.
Go with .io in a heart beat.
Obviously, if you can, snag a .com or a .net. Then if it comes completely down to it, snag a .org.
Reason being... those are extensions the average person knows.
If you grab a .co, you take the chance of either giving business to others by redirects/misspellings of .com from .co out of habit when typing fast, to whoever has the .com version of the domain, but then again it happens vice versa when holding a .com, as traffic comes from the .com's to the .co's
I snag .co's all the time, but strictly for redirect traffic purpose from typos of the .com
Out of the extensions you mentioned though, .io all the way.
I do SEO and am very very good at it, as well as me having many networks and knowing many professionals in the industry who are SEO Experts and strictly do that for a living.
.io extensions are recognized everywhere and google recognizes them as top domain extensions, not limiting them to any country.
You have the chance to get a very very strong domain with an awesome brand, and a wayyyyyyyy easier chance of ranking it in search engines.
For .PRO, you should prepare yourself for a different route of advertising and marketing because the average person does not know about the .pro domain extension.
But branding wise, if you did say your domain to someone when attempting to get business, it may result in a quick explanation of that new extension, but psycologically telling them that, you toss "pro" in their head, which will probably have a good effect gaining their trust with or without them knowing.
Also keep in mind though... .PRO is very hard to rank unless it is a domain hack with whatever your brand is.
And in my opinion, as a business professional, you do not want a company name based on a Domain Hack.
Just not good at all.
For .xyz the ranking is even harder and a I also read a recent poll (I tried to find it for the life of me because I am using it as an example for this thread, but can't remember where the heck I put it. If I find it, I will edit this and post it), in which the study showed that about 90%+ of the individuals who were shown Domains with the extension .xyz, responded that "it sounded childish", it's confusing to type in, they never heard of it, some called it stupid, and a decent percentage even said that "it was about time they made something for kids specifically".
I agree with them.
Don't get me wrong, I have sold my fair share of .xyz domains.
But branding a business with it, is not "strong" and is most likely not going to sound professional or catchy.
.io is easy to type, is growing very very fast and holds authority.
I have been watching commercials on T.V lately and was originally surprised to see that these companies were already using the .io extension... now after a seeing many on T.V using it... I'm not surprised anymore, just happy to see it's growing.
Don't be fooled by .io only being a tech domain either.
It's not.
It holds authority for anything.
And the way trends, fads and the whole shebang works...
Is that the average people online can care less that "us onliners in the industry" know that .io is a tech domain.
They are not going to care, yet alone even know most likely.
Not to mention, between all of the new domain extensions, there is alwaysssssssss going to be confusion.
We're talking about a world that grew with urls that were .com, .net, .co, .org, .biz, co.uk ect...
Then all of a sudden.. we come out of nowhere with not 1, not 2, not 20, not 50... but a thunder storm of new domain extensions and hope the average user knows them all?
No.
It's just not going to happen.
Which to me...
This is where common sense comes in.
Out of all of the domain extensions, you see business offline (who have an online presence), tons of very strong companies, tons of start ups (both tech and not tech) using the .io extension.
This should show you something just from that.
So between the shower of domain extensions we flooded the users and average person with, it works the same as Branding even if that extension stood for "Igloo Octopus".
Does not matter.
They are not going to just "know" every single one overnight.
It will indeed take time, and I personally see a largeeeee amount that sure... are doing great "selling" the extensions as registrants and the creators of the extension, congrats, but way more than half of them will never catch on and be what the average joe is going to type in.
They may arrive on it via searching something in a search engine sure...
But they will never embed ones brain as something to type in on instinct as those "words" that are now "Domain Extensions" already have been fired in their heads to mean "that" and only hold that meaning to them. Branding at it's finest.
Odds of changing what that word already means, stands for and is recognized in their brain...
Slim to None.
What we do have though... is the power and ability to take just a couple of those extensions, make them feel natural, flood the users with them and make sure the average joe recognizes them.
.io is already showing that happening. From start ups, the major companies using them, the sales via .io's Domaining and more... the .io extension is slowly taking it's rise.
I was also at a concert just a few weeks ago. It was a huge concert. Outdoors, a very large venue at "The Farm Bureau Live" in Virginia. And not 1, not 2, nope... not 5! But 8 (that I saw) had very large Tents who were Radio Stations, Bands, Food Companies and more...
They had their big banners up, and on the banner, including all of their marketing material on their table, shirts, buttons, flyers, pins (word of mouth, as I am sure people asked about their sites ending in .io) ect... was... you guessed it! Their domain with the .io extension being used and being used successfully.
I've yet to personally see that with .xyz or .pro extensions.
It's all about popularity.
Things take off at different rates. Things catch on more quickly than others.
In time, .io will be very popular and individuals will consider it as another domain extension in their arsenal of a brain to type in on instinct.
Smack a Brand on it dude. Stick with it. Rock it.
Never underestimate the power of branding.
.io is doing it bro.
Get in while you still can. And if you are still not sure...
This is your new start up we're talking about. Not Just a Domain Name.
Buy all 3 to be on the safe side, take your time, research, when settled on one, forward the rest.
And just to add something about branding and the power it holds when used correctly,
Most of us have no clue the psychological effect it has on us each and everyday...
Branding is focused on Consistence, Repetition, Exposure (and more obviously), but with those 3, their key is for you to say the name, and the logo pops in your head right away.
Or see something that looks similar in color, shape ect... and your business name pops in your end users head because of the tiniest recognition that triggers them.
If you Cut yourself... majority of people don't turn around and ask for an Adhesive Bandage. They ask for a Band-Aid.
If you're on Youtube and search for " cool dog tricks" (just made it up while typing, but search something similar and I am sure you will find it), but anyways...
You search that... Someone for sure filmed their dog and posted it. And little do you know...
In the comments for sure. And of course in the title... You will be something along the lines of "Dog Catches Frisbee In Mid Air After Doing 360".
No. It is not a Frisbee. It's a "Flying Disc".
Ping Pong rocked their brand and made the Real Name "Table Tennis" obsolete.
And don't forget the people with snot hanging out of their nose who are asking eagerly for a Kleenex, instead of a Tissue.
Branding man. Pure Branding.
I do not mean to drag on.
I am only saying this because, I want you to recognize all aspects, and make sure you remember that this question was asked on a Domaining Forum lol.
I'm not going to be surprised if a new extension comes out tomorrow and someone recommends you that one and shoots all of the others down.
Everyone has their opinion, just as I have mind on the .io
But based on facts via SEO, the stats of the amount of companies starting up with .io over all of the others, everything I see in person, not to mention my success with .io via ranking websites vs me ranking websites with other extensions, brand testing, surveys from the average individuals taken (no not us who work online), and much more...
"in my opinion, I suggest that extension".
Hope I helped some.
So... on that note...
io... io... off the way I go