Perhaps the most surprising thing I've come across in building the CommunityColor family of web sites is the large number of business web sites that hide all of their contact information.
The phenomena is especially strange for inherently local business. If you are a wedding photographer; the first question on a potential customer's mind is your location. Location is the primary concern for people looking for photographers, restaurants, kennels, hotels and the many other services which revolve around location.
I had perplexing conversations with a real estate agents who was paying out big time for unqualified leads in places where he could not practice while losing all the free leads that he would have received if he simply put contact information on his web site.
I can see why bloggers, artists and political pundits might want to hide their contact information. I think it is a grave mistake for businesses and people selling online to exclude information.
I love buying from small internet shops; However, I will not purchase from sites that don't have clear contact information. Before buying online, I check the DNS entry for your site, along with RipOffReport or other services to make sure you are legit.
If you have a web site about a business, I strongly suggest that you update the information on aboutus.org, keep accurate contact information on Alexa.com and make your domain registration public.
Unfortunately, spammers troll contact databases. In making contact information public, you should be careful to protect your primary email addresses. One suggestion is to create a throw away email address for your domain registry. For example, you might use "firstname.lastname@example.org."