.co.uk domains

Hello

I often search domain names and find that names are often taken in the .com and some others but the .co.uk is available.

I have one today and I like the name and can see a site being built around it. the .com and other are parked (Just advertising links)

Can someone tell me If I bought this domain and built a site around it what are the issues that may pop up, for example, would U.S. traffic not go to a UK domain or is that really down to gaining ranking.

Thanks