In an interesting study, "The New eCommerce Decade: The Age of Micro Targeting", conducted recently by Piper Jaffray & Co., it was found that Internet search was more efficient. It compared the customer acquisition costs of search, Yellow Pages, online displays ads, e-mail and direct mail. Customers prefer Internet to online market places for finding products and services.
The study also showed that Yellow Pages came as the second-most efficient at $20 per customer acquisition, after that comes online display ads at $50, e-mail at $60 and direct mail at $70. It is believed that with the increase of local search, the current number of 700,000 online advertisers might go upto 2- 4million over the next five years.