I don't quite know how that question relates to my post, but...

I believe its based on expand or die.

Any company needs to grow profit in order to keep the share price up. When they stop growing the share price/value of the company stalls and then falls, as long as they keep growing (rather then just cruising at the level they have achieved) prospective investors can see future profits for the company and themselves and will be willing to pay more for shares then the last person.

Looks to me like HD are keen to expand into other markets without hurting their flagship product.

Having said all that, I don't know shit so could be way off.

Maybe it was just cheap.