Who needs Cheerios when you have your favorite store brand? Sales of private label food and beverages hit $48.6 billion last year, accounting for 15.4 percent of the $315 billion in total supermarket sales. In fact, the private label segment has grown at a rate of 6 percent per year for the past five years, while the entire retail sector has risen just 3.9 percent. Just five years ago, such store brands made up only 14.2 percent of total revenues. One reason for the increasing popularity of generic products: retailer consolidation. As big supermarket chains become even bigger, consumers can find store brands in more locations across the country. Shoppers at A&P, for example, have three private label brands to choose from - a result of the chain's supermarket acquisitions in the Northeast, Midwest, South and Canada. Now, that's a national media buy.