With the help of Whrrl, Deep Focus has launched a mobile- and web-based platform for fans of the show to follow in its characters' footsteps with regular updates of their every move.

"This is pretty much the next generation of 'The Sopranos' promotion we did with HBO a few years ago when fans could search out the show's locations on Google Maps," said Ian Schafer, founder and CEO of Deep Focus.

Accompanied by character commentary -- provided by HBO -- fans can either receive or seek out tips on exactly which bars, restaurants, and clubs the Entourage crew has visited over the past four seasons, as well as the fifth season debuting this Sunday.

"One of the draws of the program is that it meshes real-world experiences with fictional characters -- so viewers really feel a part of it all," said Jon Landers, SVP of Marketing at Pelago.

A property of Pelago Inc., Whrrl is part of new bread of geo-targeted social applications, which are offering both consumers and marketers new opportunities to interact and impact an increasingly mobile world.

Among other technological advancements, the advent of the iPhone is helping to accelerate this trend, according to Schafer.

"Something like 100,000 iPhone users have downloaded the Whrrl widget," said Schafer. "That's still relatively niche, but it's a very influential group."

The Entourage promotion follows closely on the heels of a messy marketing situation in which Deep Focus was involved. Fans of the AMC series "Mad Men" apparently created fake Twitter accounts for the show's characters, which were initially taken down at the request of the cable channel, but later restored after a little nudging from its marketing partner, Deep Focus.

"This is a different animal," Schafer said. "It's good to see that there's a demand out there for this level of engagement, but we've been working on the Entourage project for several months with HBO."

Additionally, Schafer said Whrrl is better suited for this type of campaign than Twitter because of it full suite of tracking and display services. That did not, however, stop Schafer from using Twitter to announce the Whrrl/HBO deal on Thursday.

"We sent out a regular press release over the wire, but using Twitter was a nice touch, I thought," Schafer said. "It's good because not every PR person is using it to put out releases right now, and it's a self-selected audience."

Along with the Whrrl partnership, HBO is facilitating Entourage blogs, Wikis, communities and fan clubs to promote consumer engagement around the series. Additionally, Deep Focus this week is running a virtual ad blitz online.

"These are critical days with the show debuting on Sunday," Schafer said.

Whether on a mobile device or the Web, Whrrl users can share their activities including current location, opinions, notes and photos in real-time. Whrrl also provides a filtering capability using factual data -- like cuisine type or hours of operation -- alongside social data like friends' recommendations.

Founded by former senior executives from Amazon.com, Pelago, Inc. is an early-stage company based in Seattle developing web- and mobile-based consumer experiences.

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