SAN FRANCISCO -- Once again, Wal-Mart ( WMT) has started the holiday season early by cutting prices on 15,000 items -- a 20% bump in its so-called rollbacks over last year. The world's largest retailer started knocking down prices this week as part of an aggressive campaign to get a head start over its competitors, especially in a rocky retail climate that could prove especially promotion-heavy this year as chains try to drive traffic into their stores. "In an effort to help stretch the dollar, we're giving customers an early start on holiday savings with even more targeted price cuts to come," said Wal-Mart's chief operating officer, Bill Simon, in a statement. This latest round of reductions is centered mostly on household items like coffee makers, microwaves and toasters. The company plans to reveal more cuts on bigger-ticket items like electronics in the next few days. Wal-Mart slashed prices earlier this month on its list of "Top 12 Toys for Christmas," reducing them to 50%. The move keeps with Wal-Mart's traditional approach to the holidays, which is to get the season rolling before anyone else does. The difference this year is that many retailers, including Wal-Mart, are trudging through slow sales, hampered by larger economic issues and a housing slump. Mark Husson, an analyst for HSBC, points out that Wal-Mart stores have the added problem of being located in relatively distant locations while gas prices hover in the $3-a-gallon range.