The emergence of the mobile Web is, without doubt, one of the most exciting developments in the SEO space in recent times.

The relationship between mobile search and SEO poses challenges not just in terms of site optimisation and link building, but from the perspectives of usability and content delivery too. As is to be expected this early in the life of mobile search, there’s still a lot of confusion about what constitutes best practice for mobile SEO.

Should content be served on the same URL, or should a dedicated mobile site be set up on a subdomain instead? What are the pros and cons of each? How much content should be on each page of your site and what guidelines should be followed when conducting keyword research? Find the answers to these and other questions below.

Image Credit: Official Google Mobile Blog

Technical recommendations for mobile SEO

• It is important that your mobile site is standards compliant. This will help prevent search engine transcoding and ensure that it displays correctly across a variety of mobile devices.
• A mobile sitemap will assist the search engine spiders in indexing your content. A mobile sitemap generator should be used to generate this as mobile sitemaps contain special markup that identifies content as being formatted for phones.
• Google’s Mobile Site map Generator is a good bet as it offers functionality over that of other tools.
• Your mobile sitemap should be named mobilesitemap.xml.
• A “detect and redirect” policy should be configured using the user-agent variable to ensure that mobile users land on the correct version of your site.
• Ensure that there aren’t any technical barriers that prevent the search engine spiders from accessing your mobile content. An example of a technical barrier would be an age checker or login page.
• Mobile pages should be marked up using one of the following dialects to signal to the search engines which version of content is intended for mobile users: XHTML MP 1.2; cHTML; WML 1.3; XHTML Basic 1.1. This tool provided by W3C can then be used to validate your code.
• Your mobile style sheet should be named mobile.css.
• An additional iPhone-specific style sheet should also be uploaded. This should be named iphone.css.
• If running a mobile site off a mobile style sheet, a “no-transform” cache-control directive should be included in the header of your desktop content. This will prevent proxies and transcoders from serving mobile assets as part of the desktop site in an attempt to increase site speed.

Usability recommendations for mobile sites

• Unlike a desktop site, a mobile site cannot do many things and do them all well. It should aim to fulfil one or two key functions and excel at them.
• A mobile site should maintain low content volume across all pages. Rather split content across multiple pages than force users to scroll down.
• Provide the option to switch to your full website at any time. It makes sense to use a mobile phone icon to designate this functionality as it is easily identifiable.
• It is important to bear mobile display limitations in mind and ensure that this link isn’t obstructed by other page elements.
• There should also be the option to switch back to the desktop site from the mobile site in case users need it.
• To avoid confusion, these links should dynamically update to point to the mobile or desktop versions of the current page.
• A mini HTML sitemap (i.e. one that is formatted specifically for mobile) should be accessible from the mobile site as this will provide users with a reference point in case they get lost.
• A mobile site should be as fast as possible; images should be compressed, code and scripts should be kept at minimum, and assets should be stored on the same server. This is most important from a user experience standpoint, but site speed is a search ranking factor too.
• Enlarged fields should be used in forms to attract attention and reduce typos.
• When designing a mobile site and creating content for it, it is important to remember that mobile users have a different mindset, as well as different objectives, to desktop users.
• A mobile site designed and optimised with mobile users firmly in mind will have lower bounce rates and a significantly better conversion rate.
• A mobile site should feature exceptionally strong calls to action, driven by a streamlined navigation. If a mobile user is unable to find what they’re looking for on the run, then you have failed to deliver an adequate user experience.
• The navigation should be clearly labelled and logical and should appear above the fold. If the site features image content, it is imperative that it doesn’t obstruct these elements or detract attention away from them.
• Breadcrumbs and jump links (links that allow users to ‘jump’ to a specific section of a page) should be included.

Keyword research and content recommendations for mobile SEO

• Mobile keyword research differs from traditional keyword research.
• Mobile keyword research should keep the mobile user in mind and focus on mobile search volumes.
• The same page title character limit (66 characters) applies to both mobile and desktop search.
• Location-specific keywords should be included in content and page titles where applicable. This is important given that many mobile searches pertain to location due to mobile users being constantly on the move.
• If you have an existing desktop site, analytics data can prove an invaluable resource. Analysing which pages receive the highest volumes of mobile traffic can provide great insight into the type of content you should adapt for mobile.
• Many mobile searches are navigational, rather than informational; meaning that mobile users often have a clear view of what they’re looking for, and will search for a brand rather than a service.
• Optimise your rich media content for mobile. There is far less competition in the mobile video and image search verticals than there is in desktop search, and as such it is relatively easy to rank in most niches.
• Ranking in the mobile image and video search verticals will also help you dominate the SERPs – particularly for brand terms (as mentioned, a high percentage of mobile searches are for brands). Mobile screen real estate is limited, so if Google returns both traditional and blended search results for your content, there is a chance that your assets are all users will see without scrolling down.

Mobile Link Building

• Mobile links to a mobile site will inevitably carry more weight than desktop links to a mobile site (assuming these links are from domains or pages or similar authority).
• You should look to create awareness around your mobile site by publicising its launch through press releases, blog posts and Social Media engagement.
• Draw up a list of mobile directories and submit your site to these. These are an easy source of valuable mobile links that will be seen as signals of relevance by the search engines.

Serving mobile content on the same URL vs. serving mobile content on a subdomain

One of the most important considerations to make when setting up a mobile site is how you’re going to deliver your content.

The two choices available to you are either a) a dedicated mobile site on a subdomain or b) desktop content formatted for mobile using a CSS file. There are some definite pros and cons to each, so deciding on which is best for you depends on what your priorities are.

NB: Matt Cutts recently confirmed that Google allows for content to differ between mobile and desktop style sheets, provided that users and bots experience this content in the same way. In other words, you can deliver different copy and page layouts to mobile and desktop users, so long as mobile spiders see what mobile users see and desktop spiders see what desktop users see. This should allay any fears you have about being flagged for cloaking when serving content on the same URL.

Pros of serving mobile content on the same URL:

• Backlinks aren’t divided between domains (i.e. m.site.com and site.com).
• No risk of duplicate content penalties (although the chance of incurring such a penalty is slight, especially if you follow best practice).
• No chance of your mobile content competing against your desktop content in the SERPs (i.e. page x on your mobile site ranks for keyword x when you would rather your desktop site ranked).
• Removes the hassle of developing and maintaining two separate sites.

Cons of serving mobile content on the same URL:

• The primary drawback to serving mobile content on the same URL is that your content won’t be as optimised for mobile as it would be if you built it from the ground up. Usability is paramount to a successful mobile site, so this is something you should give serious consideration if you aren’t able to provide a comparable user experience to what you would get on a dedicated site.
• Furthermore, as the spiders factor in how a site scales to different handsets, if your site isn’t as optimised for mobile as it could be, this may affect its rankings.

Pros of serving mobile content on a subdomain:

• Optimal user experience and conversion rates.
• More scope and freedom from a design and development perspective.

Cons of serving mobile content on a subdomain:

• Increased development time and costs.
• Risk that you may suffer duplicate content penalties or end up competing against yourself in the SERPs (though the chance of either is extremely minimal, as in most instances the search engine spiders are smart enough to tell which content is intended for mobile users and which content is intended for desktop users).
• Diluted backlink profiles (i.e. backlinks will be split between your domain and your mobile subdomain, rather than point to a single TLD). This means that you will essentially have to double your link building efforts; this is far and away the biggest drawback to hosting a mobile site in this way.

Also check out:

• How to Think Outside the SEO Keyword Research Box
• Search Marketing Extends to Mobile
• Feature Phone vs. Smart Phone: Does it affect brand interaction amongst the youth?