Google will expand free retail listings to its main search page in a bid to fend off a growing ad rivalry with Amazon (GOOG)

· Google has announced that retailers will soon be able to list items for free at the top of Google search pages.
· The company had already changed the rules so that merchants could list items in the Google Shopping section for free – but they still had to pay for a slot at the top of Google Search. That's soon changing.
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