From headlines surrounding ad:tech San Francisco to Bing and Google battling it out for search share, the internet marketing news this week sheds some light on the direction the industry is moving.

The week started out with a report from Efficient Frontier indicating that search spend is on the rise. As Brafton reported, increased search budgets in the retail and finance industries helped boost Q1 2011 search spending. IAB shared some evidence of the value of search marketing, reporting that 46 percent of online ad revenue comes from search.

Another report from Econsultancy supports Efficient Frontier's findings, predicting that search spend will continue to grow, exceeding $19 billion in 2011. The Efficient Frontier report indicates that the company's clients are seeing more ROI on Bing than search giant Google, so marketers may want to plan search campaigns accordingly.

Continuing the good news for Microsoft, multiple search ranking reports released this week suggest that Bing is gaining ground in the search market. According to Hitwise, Google's search share slipped while Bing reached 30 percent market share in March 2011, and comScore's latest search engine ranking report places Bing at a similar market share.

Hitwise also says Bing is the winner in terms of driving traffic, with Yahoo sites' and Bing sites' referral rates at 81.14 and 80.32 percent, respectively, while just 65.91 percent of Google searches resulted in website visits. (This doesn't seem to be impacting Google's Q1 2011 revenue, which shows 27 percent annual growth.)

Microsoft's search success seems to be translating across traditional and mobile platforms. Bing search also proved to be the No.1 free iPad app this week, according to Search Engine Land. Moreover, the company launched a local Business Portal. As Brafton reported, the feature replaces the Bing Local Listing Center and makes it easier for marketers to claim and manage their Bing listing.

While the new Bing service may be exciting news for many local merchants, local marketers should keep their focus on Google for the moment. As Brafton reported, Google organic search and Google Places together drive more than half of web visits to local business sites. This indicates that Google Places listings are essential to any local search strategy.

A Google Places development this week came with the company's announcement that it will incorporate HotPot into its Places product offering. This means the name “HotPot” is gone, but Google's local social services will remain, and it may make marketers' lives simpler to have the former HotPot now part of Places.

Another move from Google that may make marketers' lives simpler is the launch of new analytics tools. As Brafton reported, the company launched DoubleClick DS3, and it previewed new Multi-Channel Funnels tools at ad:tech San Francisco.

The search giant also made headlines for this week's global expansion of the Panda algorithmic update and its announcement that user feedback is now incorporated into its algorithm.

Speaking of user feedback and Google, Google's +1 search result recommendation feature was a hot topic at ad:tech San Francisco this week. At the conference, SEO experts described the value of socially recommended search results as well as optimizing social content for searchers, explaining that social SEO is proven to drive clicks. Other keynotes predicted that social search will be the future of internet marketing.

Indeed, social channels garnered a lot of attention this week. Facebook made headlines for a rumored Groupon-style deals platform, and Matt Cutts talked (again!) about how social marketing enhances SEO, saying Tweets may help content get indexed faster.

Still, it may be awhile before social channels dominate in terms of directing traffic to sites – a report released this week reveals that search still drives the most traffic by a landslide.

Another channel that helps marketers catch clicks is email. As Brafton reported, ad:tech attendees agree that email still has value in today's internet marketing landscape. Redbox found a social email campaign boosted referrals, and other attendees spoke about the importance of strong email content as part of an online marketing agenda.

In fact, high-quality content was the underlying theme of the conference. From discussions about marketers' struggle to produce relevant content to Arianna Huffington's insight on the value of local, journalistic content, it's clear that good online content is core to any and all developing marketing platforms.

Looking ahead to next week, internet marketers may want to watch for new developments from Bing to see if and how the second-place company in search continues to propel itself forward. Stay tuned!