eBay and Wal-Mart have been developing on-site search engines for their respective Web sites -- a trend that continues to grow among tech-based companies. It's not surprising the two have been separately increasing commitments to search. ebay acquired search engine Milo in 2010 to support online shopping. Wal-Mart's tech division, known for developing and implementing emerging technologies, built a supply chain -- manufacturing and distribution -- strategy on radio frequency identification technology and real-time products replenishment.