Google received 21,389 requests for information about 33,634 users from July through December 2012, according to the company's transparency report. The Mountain View, Calif. company provided a breakdown: 68% of U.S. government official requests came through subpoenas, 22% through ECPA search warrants, and 10% were mostly court orders issued under ECPA by judges or other processes. User data requests in the second half of 2012 rose by more than 70% since 2009.

Google has redesigned its image search to run faster and more effectively. The changes, which should begin rolling out this week. include image results that display in the panel, the ability to flip through images using the keyboard, and an ability to view metadata without being redirected to a separate landing page.

David Kirkpatrick takes us through a case study on how the Chamberlain College of Nursing boosted open email rates 170% and click-through rates by 433%. Several issues presented obstacles in getting prospective students to open houses. The goal was to create an automated process to segment its email list to track prospects. Kirkpatrick tells us how the school overcame the roadblocks and breaks down the RSVP increases from different campuses.

Amanda WestBook takes us through attribution modeling in Google Analytics to show how tweaks in the new tool can change performance. The feature, which provides one custom and seven preset models, gives additional insight into how marketing channels interact and how changing credit based on position in conversion paths can influence campaign results.

Tech Crunch gives us a look at Russian search engine Yandex's mobile strategy developed by the three-person development team, who came over as part of Tweeted Times, which Yandex bought in 2011. The development team is based in the U.S. -- which makes sense because that's where Arkady Borkovsky, Yandex CTO, is based.

Adam Sutton looks at how one B2B company, Skytap, tailored content to segments of its audience, and increased leads 124% after launching. Sutton tells us that Skytap launched a content marketing strategy in May 2012 to generate and convert more leads, and how it increased North American site traffic by 210%, organic search traffic by 55%, and more.

ABI Research estimates that 145 million tablet devices will ship worldwide in 2013, supported by new devices in the market, more affordable choices for consumers, and increased adoption by business audiences. Business interest in tablets should grow to 19% of all shipments in 2013 as more PC OEMs unveil product solutions designed for the workplace.

Bryson Meunier serves up tips for mobile search engine optimization audits. He takes us through a basic mobile SEO audit using the carmaker Mercedes as an example. Citing reports, he tells us that the automaker's revamped mobile site increased traffic 170% in the past year. Begin with searching on the site. It will tell you whether the site is optimized for a navigational query and whether the company has multiple sites competing for the same keywords. Other tips include how to align the site architecture with mobile search behavior.

Some 67% of shopping carts are abandoned just before the purchase, according to Tim Ash, citing comScore stats. Perhaps the consumer thought the shipping cost was too high, like the time that ZGalleries wanted to charge $21 to ground ship a throw blanket. Ash provides three reasons why consumers might close the browser before completing the sale and reveals how to close the deal without forcing the potential buyer to search for a similar product on a competitor's site.

Julie Joyce tells us about the benefits of building social links and why they are important. She takes us through tips on building links in Facebook, LinkedIn, Google+, Pinterest, and Twitter -- along with some of the smaller sites like Foursquare, Instagram, and StumbleUpon -- but calls out MySpace as a site that brands should avoid.