What do you want to say?

Your product and your company has a core value. It stands for something.
However, the marketplace is composed of micro-markets; with their own needs and benefits that they are looking for.
When you want to be all things to all people, you lose focus and your brand promise is no longer clear. So, this is a real danger and before the more sophisticated internet technologies came and changed the way we are able to target customers, marketers were either trying to please everyone or defining their market too narrowly. Either way, they were losing customers.
Today, it is possible to do very sophisticated targeting to very small audiences with a view to precisely aligning your message to their needs. But, now the challenge is creating enough targeted "message content" which can feed the lines of communication that you have opened to sharply segmented audiences.
And as the channels themselves proliferate (mobile, web, e-mail, blog, Twitter, Facebook.. in addition to the traditional TV, newspaper and roadside hoardings ) the need to customize messages to the needs of the customers and the demands of the channels increases.