I don't see any reason why it would be essential, to be honest. With that said, it can be a good place to have an article with some good specific keywords linked to your niche and/or your area. It can also be a good place to have a few links which can take visitors to other places on your site, which will reduce your bounce rate.
You could also use it to do a little bit of pre-selling so that when people come through to the main site they are in more of a mind to spend money - assuming that you have a store. As I say, there is no reason it's essential, but at the same time it's a good opportunity to tell people how awesome you are and why you are awesome. Though I wouldn't put it in those words...