The key to optimizing mobile Websites for search is not give search engines (or visitors) any trouble getting access to your site. To achieve this I recommend you use 100% valid XHTML code, adhere to the Mobile Web accessibility best practices, and design a simple site structure with clear labels. Optimization and user experience are one.
OTA: What makes mobile search optimization different than SEO for the desktop Web?
It's not so much the differences as the importance. Mobile search is not trivial. It takes more effort to type a search word or phrase on a mobile device (especially those without a Qwerty keypad) then on the desktop Web. In spite of that time investment, studies show (How America Searches: Mobile by iCrossing) that 75% of mobile searchers are not willing to browse beyond the second page of search results. With the first mobile results page showing at most 6 items, you can clearly see just how important is for your mobile site to be visible.
Here are some SEO basics for any mobile site: * Optimize for keywords and short phrases * Include keywords in title tag, H1's, H2's and content * Think how your title will appear as a mobile bookmark * Provide keyword-rich anchor text for internal links * Get indexed. Provide Google Mobile Site Map.
OTA: Should publishers link out on their mobile Websites the same way they link out on the regular Web?
On the desktop Web search engines will analyze your links to help them rank your Website and your Web pages. The rules for mobile page ranking are not clear so for now you should assume they are similar. So the short answer is yes -- if you find a quality mobile site that adds value to your content link to it. Nevertheless, it's hard for publishers to justify the value of external linking (unless they are publishing a directory) when one considers the challenges of getting people to a mobile Website in the first place.
Another aspect of linking the mobile publisher should focus their attention on is "internal" linking. Most mobile Websites link in the linear progression, pages link to each other one after another, and do not refer to other pages on the site. What seems to work better in regards to mobile SEO is the interconnected model, where each page also contains links to other pages throughout the architecture of the mobile Website. The interconnected model has far more links shared between pages, and consequentially the potential for a greater page ranking by Google.
Keep in mind though that from a task-based approach users come to sites for different reasons. Helping them to find the right information via a direct and clear click-path appropriate to them can be helpful so do not sacrifice usability in the process of building in internal links - strike a balance.
OTA: It seems a lot of Web analytics tools don't understand the mobile Web. How can a publisher deal with this? Do they need to look for a new analytics tools? Or do they need to do things differently?
The most basic of challenge is that your mobile traffic predominately comes in through a small number of carrier gateways. Accordingly, existing tools (without separate carrier relationships) can not understand if a visitor from that gateway represents one person or thousands. For all the above reasons and more an independent publisher needs to rely on a combination of home grown tactics and device-specific experience to gleam meaningful data. We're looking at this as an opportunity and are developing tools to solve some of the problems. Our recent release at Winksite, "Winksite Releases Major Upgrade - Love the Mobile Web," was the first step. Analytics come next.
OTA: What role do the carriers play in mobile SEO? Do their networks make optimization harder?
The very nature of how carrier directories work (or don't work for that matter) drove people off deck in search of the content and services they were looking for. This didn't make optimization harder it made mobile search and optimization obvious and necessary. Helio in the US, and T-Mobile & Vodafone in Europe are doing a better job then most and have embraced more open models. This makes sense if they wish to continue to play a role in the future of the mobile Web, especially as the walled gardens continue to crumble. People are looking for direct connections to their friends, feeds, and favorites. They will use what delivers that to them. The next step is aggregating and personalizing those connections.
OTA: Besides search what are some other ways you can begin to grow traffic to your mobile site?