From headlines revolving around the Google I/O conference to evidence of the increasing importance of social media campaigns, the week ending May 13 was full of online chatter from the internet marketing community.

Google previewed the +1 button at this week's I/O conference. Marketers can add the social plugin to their content pages to encourage visitors to recommend their sites. The +1's will then appear on search results pages. The much anticipated +1 button is supposed to be available in the next few weeks.

However, some may be wary of +1 in spite of the hype in light of certain “whispers” about Google and social data. Facebook and Google went head-to-head when the social giant's attempt to start a smear campaign against the search leader was revealed. Facebook officials want to shed light on the fact that Google users can't opt out of social search – Gmail users can manage their privacy settings, but other searchers' social data will be used to fuel Google's social search. Google hasn't spoken about the allocations yet, but Facebook maintains it had valid reason to hire a PR firm to start a whisper campaign.

Google and Facebook also went head to head as both announced image features this week. Facebook unveiled a new image tagging feature that allows users to tag Pages in the same way that they would tag friends. This will help social marketers get more user-generated content, and it stands to boost brand engagements on Facebook.

For its part, Google unveiled a “sort by subject” image service. This makes searching for images more visual. (For instance, searching for “coffee” and choosing to sort by subject organizes the image results into categories such as “cup of coffee,” “coffee beans” and “people drinking coffee.) This means content marketers will want to tag their images with nuanced SEO in mind.

Google also launched a new kind of computer this week – the Chromebook. Announced during the company's I/O conference, the Chromebook will be available on June 15 and – as its name suggests – it relies heavily on the Chrome browser.

Another Chrome-centric development that made headlines this week is the Whoworks.at extension for Chrome. As Brafton reported, the extension allows web searchers to see which of their LinkedIn connections is affiliated with a site they are visiting. It is a step toward bridging the gap between online content, social media and (potentially) business partnerships. Of course, the extension is only useful for social content marketers if users browse the web with Chrome – and perhaps the Chromebook will help on this front.

Google is also doing well on the mobile search front. Android is the top smartphone OS, according to comScore's most recent mobile subscriber report. As Google gains ground, RIM is losing market share – just as it announced its partnership with Microsoft to make Bing the default search engine for BlackBerry.

Even if it still lags behind Google in both the mobile and overall search market, Bing is ascending and search marketers should take note. The latest search engine ranking report reveals that Bing now accounts for 14 percent of the search market. Meanwhile, Google's share has flattened (at best).

Microsoft also came out victorious this week when it announced its acquisition of Skype. Both Google and Facebook had been trying to purchase the video conferencing system, but it seems Microsoft proved the highest bidder. This acquisition might help push Bing further up in the search rankings, as it will connect Microsoft to Skype's large user base.

Of course, as internet marketers monitor Bing's weight in the world of search (planning SEO and paid search campaigns accordingly), they can't ignore the fact that Google is still search king. To help its search partners, Google offered new Adwords targeting for tablets this week, as well as an API for Page Speed Online which will help site developers improve SEO.

Another Google/SEO development may be around the corner in light of the company's experimental new search results pages. As Brafton reported, the company is testing a new results page layout (which is getting mixed reviews from users). Marketers should note that the new layout displays fewer organic listings above the fold, which means commanding top rankings – and ramping up SEO efforts – will be increasingly important.

Those who want to boost their Google SEO might consider news content marketing. Google announced a “News near year” feature for mobile users, prioritizing locally relevant headlines for Google News users. This comes on the heels of Google's inclusion of linked news headlines for news-related general web searches.

The online demand for optimized news content is increasingly clear, as Pew recently released data suggested that search is the most common way for Americans' to find headlines across the web. The study also found that Facebook is gaining ground as a traffic driver to news content, suggesting brands should share news headlines across the social giant.

Sharing unique and high-quality content is one of Facebook's top social marketing tips, according to the marketing guidelines the company released this week. Social media marketers looking to boost brand awareness, traffic, leads and sales might consider consulting the social giant's best-practice resource.

Of course, it seems a number of businesses may not think they need Facebook help. As Brafton reported, a large share of CMOs say social media is already producing measurable ROI for their companies. The majority believe social marketing has the potential to drive significant return on investment.

Businesses focusing on social sharing shouldn't forget the value of email marketing. Brafton reported that a recent survey shows email is the top content sharing platform among women, and marketers may find email campaigns breed female brand advocates.

Of course, internet marketing in all of its forms is becoming more closely related to sales. The latest ecommerce figures suggest that consumers are increasingly making online purchases, with web sales hitting $38 billion in Q1 2011. This shows strong year-over-year growth.

Next week, we might expect more news about the ongoing battle between Facebook and Google, as well as insight into how marketers might benefit from the recent Microsoft/Skype alliance. Stay tuned!