In general if you plan on building a serious business use .com or the owner of the dot com will be happy with all the free traffic your .co will send them
Do two things to get a feel for what's happening with .co and Colombia.
First do a search on Google using the 'site' word like this "site:.co" and combine with a few keywords that you might be familiar with or to target your business idea "restaurant site:.co" for example. Read the results and click through to look at the websites. Notice many forward to '.com' for example even adding a second word presumably to keep the .com cost down.
Second for Colombia, seek out country specific search results on google.com.co or otherwise. News, travel, maps, restaurant in Spanish etc. Which extensions are they using? It's been a while now. Colombia companies still using ".com.co"? Not sure if that sentiment has changed.
In the past the quick discussion was solid one word .co might work for business or flip domaining. More than one word .co don't buy it for business or domaining. You should be able to get two word .com at reasonable price for example (few thousand $$$$).
Maybe someone else will reply to confirm this, I could be out of touch with current happenings.
.CO is one of the best non-coms in my opinion right now. It is widely used and accepted with single word .CO's reaching hefty price tags. I like it better than xyz or .net.