Today marked the first full day of ad:tech San Francisco sessions surrounding SEO, social, mobile, email, social gaming, geosocial (you name it, the ad:tech attendees talked about it!). While internet marketers, industry analysts and tech developers talked about a bevy of ways brands can reach out to their online audiences, one thing seems clear – quality content is the glue holding together any successful online marketing campaign.

Brafton sat in on many of the informational sessions and debates about the future of the internet marketing industry (and you can see all of our live coverage in our newsroom), and here are six key takeaways for content marketers:

1. Write to the right audience.

Guy Kawasaki may have famously said “Content is king,” but maybe we should amend that to “Relevant content is king.” Many of the industry experts at today’s sessions were clear that producing relevant content is an area where internet marketers struggle – and relevancy is increasingly key to catching clicks in a cluttered online space.

Joseph Carrabis of Critical Mass and iMedia Connections went as far as to say that failure to appropriately target audiences is the No. 1 mistake he sees businesses making in terms of ecommerce.

“SEO for ecommerce” expert Rob Snell also cited relevant content as a critical factor for both positive rankings and conversion. He shared statistics proving that content which is useful to site visitors, teaching people about a brand’s market and services, lifts conversion. Sites with buyers’ guides and relevant content saw 50 percent higher conversion rates than others he studied.

For marketers, this means you’ve got to do your homework on your online target audiences. Assess prospects’ informational needs and the keywords they are searching, then plan content campaigns accordingly.

One key way to get a pulse for what your prospects are searching is by keeping on top of trends as they relate to your industry. Google Trends, Realtime search activity and Twitter trends can help in this department – which brings us to the next point.

2. Pay attention to social SEO and social search.

The value of social SEO was lauded across the board at today’s ad:tech San Francisco sessions. Content guru Lee Odden said that social should be a core component of any SEO marketing campaign, mirroring Matt Cutts’ declaration that social content can boost sales rankings.

The ad:tech attendees were also buzzing about the value of getting positive social mentions to advocate your content in search results (such as through the Facebook data included in Bing social search, or via Google +1s).

Antonio Lucio, CMO of Visa, boldly bashed Google – saying the search giant is going to have to move into the social space if it wants to remain relevant. He claims his billion-dollar company already focuses on social search and it seems to be working for his brand – last year, 20 percent of Visa’s business was ecommerce.

Brafton has reported that Google is trying to get into the social space – and this was widely discussed at ad:tech. Google’s +1 and other new developments, including Twitter’s new SEO-friendly features and Facebook’s potentially patented forays into search, were all explored as evidence of the growing importance of social SEO.

So what can marketers do? Share optimized site content on social media and optimize original social content. This is also something Brafton has written about in the past – check out our related blog post on Twitter SEO techniques.

3. Use strong email content to drive social engagement.

So with all this talk about social media, email marketing is obsolete, right? Wrong! There was plenty of talk at ad:tech about how email marketing it still relevant, profitable and overall good practice.

Jeff Rohrs, the vice president of marketing at ExactTarget, shared some recent research indicating that 93 percent of consumers are email subscribers, and the insight he shared reveals that consumers across age groups are increasing their email usage. (Brafton reported on some of his presentation in an earlier news article about email marketing as a must.)

One point that a number of attendees emphasized is the value of pairing email marketing and social media marketing to enhance both efforts. Ryan Tuttle, vice president of strategic services for BrightWave Marketing, says American Airlines’ thoughtful email content garnered more than 250,000 Likes for a new Facebook Page, and Chic-fil-A both drove Facebook engagement and built its email subscriber list with a social contest that it tied to email marketing.

Brands should be delivering fresh content to email subscribers, and they should be integrating this more traditional online channel with newer social platforms. Take a page out of Chic-Fil-A’s book: Start a contest on social pages and notify email subscribers of it via their inboxes. Then, ask social users to sign up for emails to receive contest updates.

A simpler practice that all brands can – and should – adopt is including social buttons within email marketing messages that make it easy for email recipients to become fans and followers.

And when creating email messages, don’t forget that mobile email opt-ins are rising… which brings us to a point about mobile content. We’ll explore mobile content and more in an upcoming blog – so stay tuned for Part 2!