I can't say about Colnago, but I will stick my $0.02 about Cinelli. No, they don't have a huge market share in the US. But they are a pretty big hit with the hipsters. They are targeted with the RVCA, Mash and Gazzetta. Cinelli is a major sponsor of the CMWC and the ECMC. With this, Cinelli is targeting the early adopters, something that will give them the reputation as leaders and will keep their bikes desirable for some time.
Also, Cinelli is one of the first companies to use stainless. And while the die-hards here insist upon lugged construction, in reality, lugs only offer a different aesthetic, it is not "better". Instead of being a slave to the past, Cinelli looks to current trends and brings steel bikes forward with their XCR, whick I personally would consider a modern classic.
IAB - I'm not talking about Cinelli's entire line, or Colango's. I'm talking about those two particular bikes.