Google, by helping to facilitate transactions and redemptions of coupons and discounts, may also be able to gain insight into consumer-spending behavior, said a person familiar with the matter. A representative of Wal-Mart Stores Inc. confirmed the company had a briefing with Google about the technology, but characterized it as very preliminary discussions and said it hasn’t been asked to adopt it. The local business ad market is a massive opportunity that has begun to be exploited by Internet companies such as Groupon Inc., social network Facebook Inc., and business-reviews site Yelp Inc.