Three Reasons Amazon Will Keep Stealing Business From Wal-Mart and Best Buy

But Amazon will continue to gain market share in electronics and general merchandise, according to a recent report by Trefis.

The report lists a few reasons why Amazon will continue to dominate.

• Online retail sales are growing. Holiday retail sales on the web are expected to jump 4% this year, according to the National Retail Federation. Online shopping is getting more common all the time, which will "fuel Amazon's growth" going forward, according to Trefis.
• Amazon is expanding into new markets. In addition to staples like electronics and books, Amazon is making investments in apparel and consumer staples like toiletries. "While eBay has been concerned about slowing e-commerce growth in the U.S, Amazon doesn't seem to feel it," Trefis writes.
• Prime memberships are becoming more popular. The company says it has added millions of new members this year. These customers are incredibly lucrative for Amazon. "Prime customers tend to buy twice as much as the regular customers and overall accounted for 10% of the purchases in 2012," Trefis writes.