Barnes & Noble announced today that it's opened up the Nook to third-party developers and content providers. The company also introduced a new suite of developer tools and services for the color version of the Nook including software for debugging apps and the ability to connect with other developers and technical experts. Third-party apps will be subject to a review/acceptance process and the company will take a 30% cut of revenue from paid titles. B&N initiated the Nook developer program last fall. More information is available here.

What with rising gas prices and a late Easter holiday, shoppers had plenty of reasons to stay home in March, but while retail sales fell from the previous month, they still came in higher than expected. Kantar Retail says March sales rose 2.5%, compared to 4.4% in the prior month, and 9.2% in the March a year ago. The International Council of Shopping Centers , which tracks a slightly different group of stores, says its index registered a 2% gain, on the high side of its expectations. "This gain, in the face of somewhat adverse factors, was encouraging and …

In a new forecast, Gartner predicts worldwide smartphones sales in 2011 will increase nearly 58% to 468 million and that Android will be easily the most popular mobile operating system by year's end, with 38.5% market share. By 2012, Gartner expects that share to grow to nearly 49%. The research firm also projects Windows Phone becoming the second most pervasive smartphone platform by 2015, with 19% share, on the strength of Microsoft's recent alliance with Nokia. IDC issued a similar forecast last week, projecting 49% growth in the smartphone market and Android becoming the dominant platform this year, with …

At a time when some conventionally wise people believe print may be dead, Hearst Magazines is teaming with Scripps Networks to bring its HGTV network to print, with plans to launch HGTV Magazine this fall. The title, which will focus on themes covered by the TV network, will be edited by former Coastal Living magazine Editor Sara Peterson, who will serve as editor-in-chief. The first two test issues will feature HGTV talent throughout its pages, offering readers personal tips, tricks and expertise, as well as a behind-the-scenes look at their shows. Content will include real estate, decorating, home renovation, …

Major League Baseball Advanced Media has turned to Auditude  to power video ad-serving on MLB.com across live game streaming, video-on-demand (VOD) content, all individual MLB team Web sites, and on smartphones and tablet computers. Last week, MLBAM launched the latest edition of its popular At Bat app which sells for $15. Auditude, which has previously partnered with companies including MTV, Comcast and Lionsgate, said its latest deal would allow brand advertisers to create custom units and run integrated campaigns across MLB properties. As part of the agreement, Auditude will also help to sell MLBAM’s video ad inventory. During the baseball season, …

Healthline Networks has launched a mobile-optimized version of its flagship Healthline.com site complete with popular features like SymptonSearch and TreatmentSearch. The company also offers mobile ad opportunities through the Healthline Media Network, which it says reach 30 million people each month. "Because Healthline mobile is optimized for smaller mobile device screens, it's simpler for users to access our health content in a streamlined mobile experience and it's easier for healthcare marketers to engage consumers," said David Kopp, senior VP of consumer media at Healthline, in a statement. Read more here.

In a bid to strengthen its positioning as a wellness brand, Walgreens is launching Walk With Walgreens, and will sponsor 5,000 community walking events around the country. Consumers sign up and then log in their steps on Walgreens' dedicated website, earning rewards from such brands as Unilever, Coca-Cola, and Johnson & Johnson, as well as gym chain Lifetime Fitness and Famous Footwear. Those who participate in live events get a pedometer and logbook; others can download digital tools on its website. "Walgreens' brand purpose is to inspire wellness, and certainly everyone knows there's a pharmacy in the back …

Mobile in-game ad startup Kiip has secured a $4 million first-rounding funding from investors led by Hummer Winblad Venture Partners and including existing investor True Ventures. The company will use the new capital to expand hiring and build out its technology platform. Co-founded by 19-year-old Brian Wong, fellow ex-Digg executive Courtney Guertin, and Amadeus Demarzi, previously of San Francisco design agency Sequence, kiip is still in stealth mode but plans to formally launch at ad:tech in San Francisco next week. In connection with the investment, Hummer Winblad partner Lars Leckie will join Kiip's board. The company also announced …

Havas Digital has been named digital agency of record for The Economist.  Havas agencies involved include media unit Media Contacts, creative agency archibald ingall stretton, and social media agency Cake.    The Economist's previous digital agencies included Morpheus Media and Digital Root.

Luxury watchmakers found plenty to cheer about at their recent Baselworld trade show, with attendance up 2.5%--bringing attendance at the trade show to its second-best year ever. And amidst the usual celebrity fanfare--including Jacob & Co. introducing actress Milla Jovovich as its new "Jacob Girl"--attendees say sales of time pieces and high-end jewelry were brisk. Buyers, especially from Asian regions, seem confident that consumers are ready to step up and splurge on more bling. Patek Philippe says it achieved record results, for example. Chopard also says its sales were up, and TAG Heuer claimed double-digit gains from the prior …