Social Media for Small Business - Is it Worth?

Social Media has become #1 searched network on internet. This increasing popularity also attracting lots of business to be part of it.

How they start - create social presence , open accounts/groups/pages on these social sites.

Will people care about your pages more than their friend/family?

Then Try to bring more users to these networks - from website/advertisements

People may start following you on these networks, How it is different that RSS?

Then start selling - Can we sell something when people are in their social mood, will they make their buying decision on these networks?

Is this a right way to do use social media?