By far the .com domain name extension is the most popular. It was the first one way back in the early 90s and everyone fought over them.
Today (that's in 2011, for those reading this in the distant future) it seems like there are new dot extensions every few weeks. The .co extension is newly available and now you can even register a .asia extension, if you really wanted.
Many of our jewelry stores have difficulty acquiring the domain name that perfectly matches their store. But some stores find that another store with the same name already has the .com. In these cases, we always recommend selecting the .net or the .biz options.
Just the other day there was a discussion in our office about the validity of the .co domain extension. However, the point was brought up that human muscle (typing) memory would probably k...