Some people do register names based solely on ovt.
Ovt numbers should be taken loosely. On one side, it does show you what people are typing in many cases. But someone could also search for a term multiple times to make sure that it shows in the keyword tool a few months later and they could charge more for their domain name.
Ovt isn't entirely accurate with the terms. For example, you put in the term paradise poker, and it will show you 14639 for that, but I know for a fact that a lot of people are searching for poker paradise but Ovt just puts them together. Same with Xbox, Ovt will show you x box, but most people are not adding a space.
You can also put in domain names with extension, as in namepros.com, and you'll see how the number (61) is obviously very inaccurate and can't be trusted to show how much traffic a name is getting.
Personally I think that Google results are silly to use to show a domain name's value. Oh wow! 145 results for "they potato". Someone had better register theypotato.com fast!
I think it's a good idea to show the ovt results when you're selling a name, if the numbers are good. If they include the extension, then definitely do it.
So if your domain name is crazycowpuppet.com, you'd want people to know that Ovt shows 37 for April for the term crazy cow puppet.
Now if it showed any number at all for crazycowpuppet.com, that means people are typing the domain name, and that's even better.