question Is so special in .co domains?

.co is popular

It is Colombia but, also works for company.

What does it mean when a company name contains "and co."?

It may means there is a sizable company of which this person is a part, but many consultants set themselves up as 'John Smith and Company' (what 'co.' usually means in North America) and there is no one else. ... What is the meaning behind “& Company” in some company names (ex. NY&Co.)