Give Gmail address to a retailer? They'll have an easier time showing you ads on Google

Gmail addresses are about to become a valuable advertising tool. At an advertising industry conference in New York during the week of Sept 28, Google is expected to debut a system for businesses to direct ads specifically to consumers whose e-mail addresses they already have on file. Someone who has signed up for, say, a frequent-flier program with a Gmail account, or has an e-mail linked to a Google account, might get ads from the airline that show up just to that person and other existing customers.

The airline could already buy ads that display alongside search results for “flights to new york.” But with the new program, it can focus attention on loyal customers, theoretically spending less money to have ads show up only to people who already have some relationship with the airline. The targeted ads work just as well on other Google properties, wrote Sridhar Ramaswamy, Google’s senior vice president for ads and commerce. Google said the new tool helps advertisers message their “highest-value customers on Google Search, YouTube, and Gmail -- when it matters most.”