Wal-Mart moves in for the kill in electronics

Wal-Mart (WMT) has a history of disrupting industries by entering them with low pricing and broad offerings. The $4 prescription is one recent example.

The world's largest retailer is now looking at the Best Buy (BBY) and Amazon (AMZN) electronics franchises and wants a piece of their pie. But the two companies may not be such pushovers.