Should I get a .co or .com?

I'm currently deciding if I should get a domain name of my 1st choice but with a .co (instead of a .com) or if I should get a less preferred domain name with a .com (because my 1st choice of .com is taken).

So I have some doubts to clear.

1. Is .co the next big thing or it is just a fad?
2. Do the search engines treat .co and .com differently?
3. Should I go for 1st choice name .co or less preferred name .com?

Do the search engines treat .co and .com differently?

No, they do not.

Should I go for 1st choice name .co or less preferred name .com?

If your target audience is local, then having the best possible domain name in a local top-level domain is generally better than having a weak domain name in a global top-level domain.

If your target audience is global, then try very hard to get the .com. See if you can come up with a good name for which you can get the .com. If your company is a venture-capital backed startup with high growth ambitions, then consider buying the best domain name with cash or equity even if it is expensive. If you're bootstrapping, then get creative with the name instead.

Search engines don't care which top-level domain you're on, but some users may. Many users expect to find your company on "brandname.com" , and some users don't trust alternative domain names such as .co, .biz or .us as much as they do .com .

This has been answered here before. The simple answer is, unless you are only selling to people within your own country AND your country has a tradition of using .co, .com is the only way to go.

From my previous answer- What is the purpose of the web site and who is the target audience? If you are trying to sell something, or just deal with the general public .COM is the only choice. How many times have you mistyped someone's email address because it ended in .net or .org? You mistype the email address because you have been trained, since the day you first went on the internet, that all internet addresses end in .COM.

A .COM address is reliable, trustworth, and normal.

The .NET and .ORG addresses are odd, but acceptable. Nowhere near as good as .COM though.

The .EDU and .GOV addresses don't count since you can't really get one of those.

Any other address is suspect. It is not normal. Why trust something strange? Other addresses scream "I couldn't do better than this. I'm desparate, so this is what I got."

Per SEOmox TLD rate better in some cases because of how spam detection works in other cases because it is rated better by Google.

http://www.seomoz.org/knowledge/domain http://www.seomoz.org/blog/know-your-playing-field-the-real-top-100-domains