How much notice did you give?
Did you also change your site? Or did you just change references to the old name to the new?
Is there anything you think people should think about and consider before changing the company name/site domain?
EDIT: Want to give my own experience too.
For me...
Changing my domain name was a very good move.
My old domain was linked to from a lot of sites but it was losing a lot of traffic because firstly it had a hyphen and secondly, it was .net and someone bought the .com after I got the .net
When I got a new domain I kept both these things in mind as they both meant I was losing traffic.
I then got a new domain that didn't have a hyphen and I got com, net and org.
I removed everything on the old domain and put a link to the new domain and let people know that the site had moved.
I let customers know about upcoming changes at least a month before the move.
The new domain was put on a different server from the old and it was available as soon as I closed the original domain, including all support.
I kept both emails going, for both domains, and I have done until now.
I just thought about it when I read this thread and I'm going to close the email for my original domain, it receives a lot of spam and everyone uses the new domain now.
I wanted to keep both running because a lot of people were still using the old domain after we moved, even for a few months after.
I suppose I could have just forwarded it but since I had it setup in an email program, it was just as easy to have both running.
I really haven't done much marketing since I changed to the new domain but I will be doing that soon.
I did a lot of marketing in the old domain, a lot of which was wasted because traffic was going to the wrong sites when people tried to remember the domain from the top of their head.
If you are moving to a new domain that is easier to remember and people can type it in their browser without having to check what it is then it is well worth the domain.
It will get more signups, I know because I had a few people contact me when I was on the last domain saying they went to the wrong site and didn't even know it wasn't the site they were looking for since it was another similar company.
John