escalated Tuesday and caused a maelstrom of speculation for other local-oriented companies, boosting stock prices for public local firms Friday and coinciding with eBay's ( EBAY) buy of Milo.com and Amazon's ( AMZN) investment in Groupon rival LivingSocial. For giants like Google, the appeal of Groupon and its rivals is their knowledge of locals' buying and searching habits -- valuable data as big, global firms move into smaller markets with targeted search and advertising. Groupon, which offers customers a daily discount from local businesses, could be mulling an IPO, reported Chicago Breaking Business. Like Google, Groupon completed a series of its own acquisitions this week, buying three daily deal sites overseas and a technology company in California. --Written by Maggie Overfelt in New York. >To follow the writer on Twitter, go to http://twitter.com/maggieoverfelt. >To submit a news tip, send an email to: email@example.com.