In the 'good old days' - about three years ago - you used to keep in-touch with your customers using phone calls, email messages and face to face meetings. Nowadays the world has changed. People expect even more frequent updates, yet it's nearly impossible to meet with every business contact on a regular basis.
Thankfully, blogging has come to the rescue. Setting up a blog on your web site - and having an associated RSS feed - means you can keep in constant touch with your clients and potential customers. Plus you don't have to email them and they can get your latest news without having to visit your web site.