Your website visitors come to your website to find out what's new. If you're not eloquently communicating with them about your latest and greatest then you've probably lost a customer.
A website is a tool for communication. Are you using it as that? Most websites of small businesses are easy to beat, because they aren't trying. A website that succeeds at useful communication will absolutely increase sales.
We love the mystery the develops around objects like roller coasters as they age. Still the same coaster but a little rusty and dented. This is not the case with your company. People want to see your website freshly shined with the latest exciting information. If they aren't getting that, they'll find it elsewhere.