I am not a demographic. I am a person. And your customers really notice when you take time to notice them as an individual. Yet as Mary points out, too often we go for the cookie cutter approach.
Remember back in school where everyone had the same notebook on Day 1? But by day 3 all the notebooks were different. So do the same for your marketing. I was talking to a large print shop and they have the ability to print unique catalogs for each customer, even on runs of over 100,000. Amazon customizes your page the same way.
So make sure your web site is unique, and make sure your collateral is customized just for the people you are talking too.
But, you say, we sell to everyone! I hear that and I know your sales are flat because you are not relating to anyone in particular. And that's an easy problem to correct.