As time goes on, and more and more top level domain names have been purchased, leaving attractive ones available, dentists who wish to use their dental practice name on the internet, or particularly geo locators ie dentist & london then you have to try and find different ways to achieve the result you desire ie londondentist.co.uk will obviously have already gone, but alternatives such as london-dentist.co.uk or london_dentist.co.uk might still be available.
One way is to use an underscore (_) another is to use a hyphen (-), Google have specifically stated that the hyphen is preferable on its search engine, which is obviously why we have chosen Dental Hyphen Design (dental-design-products.co.uk) as our domain name.
Matt Cutts, in his blog on Google called Dashes vs. underscores explains the situation:-
I often get asked whether I’d recommend dashes or underscores for words in urls. For urls in Google, I would recommend using dashes. Why? To find out, let’s take a trip in the Google Time Machine. Set the dial for 1999, the year Matt first discovered Google. Matt was using, I dunno, maybe HotBot at that point? The curtain rises:
Matt: Hmm, this search for [FTP_BINARY] didn’t turn out the way I wanted. I got a couple scuzzy looking urls, and the other documents just have the words “FTP” and “BINARY” but the term “FTP_BINARY” doesn’t actually appear. (Note: Matt was a bit of a nerd, as you can tell.)
Some Random Person That I Don’t Remember: Have you tried Google?
Matt: What’s that?
SROTIDR: It’s a search engine written by nerds for nerds! They index numbers! Sometimes they even index punctuation, like “C++”. Try your underscore search there.
Matt: Okay, here goes. Whoa! They actually return pages with the literal string “FTP_BINARY”! That’s wicked cool! (Did I mention Matt was a nerd? Big-time nerd.)
SROTIDR: Yeah. The wild thing is that they wrote a paper about how they crawl the web and rank pages.
Matt: Well, now that’s just silly. I wonder why they didn’t keep it a secret? I bet those papers will make great reading for my information retrieval class.
I’ve stylized the conversation quite a bit, but I remember how impressed I was that Google indexed numbers and some punctuation (come to think of it, search engines have come a long way in five years). With underscores, Google’s programmer roots are showing. Lots of computer programming languages have stuff like _MAXINT, which may be different than MAXINT. So if you have a url like word1_word2, Google will only return that page if the user searches for word1_word2 (which almost never happens). If you have a url like word1-word2, that page can be returned for the searches word1, word2, and even “word1 word2″.
That’s why I would always choose dashes instead of underscores. To answer a common question, Google doesn’t algorithmically penalize for dashes in the url. Of course I can only speak for Google, not other search engines. And bear in mind that if your domain looks like www.buy-cheap-viagra-online-while-consolidating-your-debt-so-you-can-play-texas-holdem-while-watching-porn.com, that may still attract attention for other reasons.
This article was reproduced with thanks from Matt Cutts blog