Do you as a brand owner have to twitter?
Do you need a blog, a social network, a youtube channel?
The Romans coined the phrase: panem et circensis.
Your brand and its offering are part of entertainment?
Then you should actively participate in web 2.0.
Actually, you should aim to take a leading role.
Your brand and its offerings are closer to the bread category?
You will survive without.
The vast majority of people will continue to be influenced by classic media when buying the very basic products and services.
They will not follow the blog or tweet of their baker, butcher, supermarket, hairdresser or auto repair shop. The menus from all the delivery services under my door are a pain already, do I want emails from them on top? Certainly not!
And if you are good at your job – offering a better value -, your existing customers will blog, twitter and post for you.