Greeters in Wal-Mart

I was in Wal-Mart today and was greeted by a smiley elderly lady "How you doing?". I would have said "Good, how about yourself?" and walked away towards the cereal section. But I stood there by their entrance wondering, why does Wal-Mart pay a person, albeit minimum wage to stand at the entrance greeting all those pass through those automatic doors. Wal-Mart wouldn't be paying minimum wage, without any benefits if there is no tangible ( read a monetary) benefit.

A wal-mart greeter

What could be the benefit though, I have searched the best I could and found that Greeters are not that friendly of what they are supposed to be.

She came up with the idea of posting an employee at the door to check shoppers' items. Wal-Mart headquarters in Bentonville wasn't willing at the time to pay an employee just to do that job, Richard said, so she suggested employees take turns volunteering a half-hour each day without pay

The Morning News :: Wal - Mart Page

So in other words there are security guards masquerading as greeters, with a disarming smile. But what is funny is they are usually senior citizens. But, I cant imagine a grand ma chasing a pimply faced teenager with a DVD of Star Trek hidden under his T-shirt.