• by Mark Walsh  @markfwal, June 26, 2007

Circuits are overloading on new 411 services. Google recently launched a free voice-activated local business search 411 service, on the heels of Microsoft announcing plans to acquire voice-search platform provider Tellme Networks, reportedly for more than $800 million. Yahoo is also exploring ways to link voice input technology with its mobile search results.

Then there’s existing services such as Jingle Networks’ 1-800-FREE411 and AT&T’s 1-800-Yellow Pages, which require users to listen to brief ads before receiving directory assistance. Yellow Pages also recently unveiled a text-message option, YP411, for listings via mobile phone. Businesses can then be called directly from the search results.

At stake are big dollars. The Kelsey Group estimates that traditional directory assistance providers — charging $1.50 per call — generated $9.4 billion in 2006. “The voice and text-based directory assistance model is where a lot of mobile search will happen,” says Greg Sterling, principal of Sterling Market Intelligence.

To help directory assistance operators and yellow pages businesses compete with online upstarts, mobile ad supplier PhoneSpots, which powers YP411, has started a mobile ad network that places relevant ads near search results sent to mobile phones. “We’re giving 411 providers the ability to monetize their local search inventory using mobile data ads,” says Rod Stuhlmuller, vice president of marketing at PhoneSpots.

The ads can take the form of enhanced listings or call-to-action spots priced on a pay-per-click or per-call basis.