Responsive Design or Separate Mobile Site, App
The days of thinking of mobile as something you can get to later, when the mobile traffic arrives, are over. 

Mobile makes up a major share of overall web traffic -- this is undeniable. In fact, various sources have reported that mobile traffic volumes will overtake “traditional” traffic as soon as 2014.

If you haven’t already figured out how to attack mobile with your own website, you simply cannot wait any longer to get serious about it. This goes beyond simply cobbling together a mobile app -- it must affect the very architecture and approach of the website itself.

Some clients of ours have been waiting to optimize for mobile because they are unsure of the right way to do it. In helping them sort through the issues, we have spent a great deal of time analyzing the options.

In the end, the decision really comes down to whether you convert the whole site to a responsive experience (i.e. the same website responds to the size and platform of the browser and serves up a different experience for each) or build a separate mobile-optimized version of the website for devices such as smartphones and tablets.

SEO Implications

From a strategic standpoint, SEO should play a significant role in this decision. In reality, your website can succeed at driving organic traffic no matter which direction you choose to go.

With Google increasingly emphasizing mobile as a requirement for overall ranking, you need to build in time and resources to SEO the site as part of the upgrade or build out. But you need to do it responsibly. How can you best balance a custom experience for all platforms with targeting for the search engines?

We saw in the old days that a lot of webmasters chose to overemphasize SEO at the expense of user experience. Those websites did okay until Google Panda hit. Today, you have to keep content/page quality and overall experience in mind to rank.

The decision point here comes down to the amount of effort it will require to rank the mobile website. Which would you prefer:

  1. Build one responsive website that pursues the same keywords on any platform, but that adjusts dynamically to the interface being used to view the site.

  2. Keep your existing traditional website live, but also build a second website targeted to mobile browsers. The mobile site will provide more control over the user experience and custom mobile targeting for the same or different keywords. Both must be optimized and crawled separately as subdomains, so both will rank independently depending on platform.

Many enterprise webmasters swear by option number two as the right answer for various reasons, the most visible of which is the ability to completely control the experience on mobile. That sounds great, but only if you plan to invest in a full SEO campaign supporting both websites independently.

Rather than overboil the ocean, I always opt for the most efficient path. In this case, responsive is hands-down the easiest to optimize and grow for organic search traffic.

Advantage: Responsive Design

Development and Content Management Support

SEO is not the only place where support resources factor heavily into the decision. If you build two websites, you have to support two websites.

This includes having to update both sites every single time you want to add pages, change content or branding, modify a template and pursue new keywords. I've worked in and with enterprise development support teams, and they share one important characteristic: they operate with a perpetual lack of support resources.

Businesses tightened their belts as much as possible during the recent economic downturn. Many dev teams are now being forced to make significant tradeoffs between conflicting priorities.

If efficiency matters, a single website makes the most sense. Surely, some companies have ample staff to throw at an additional website. That doesn't mean it makes sense. Imagine what types of major additional projects your dev team could take on if you cut their tactical website support time by 33-50 percent.

Advantage: Responsive Design

User Experience

User experience impacts the success of your website in a myriad of ways.

First, users expect world-class load time, usability and interactivity. If a custom mobile website can truly offer the best possible experience on mobile, then this is one area where it would be the best option.
At the same time, there are benefits to presenting a consistent experience across the two platforms. Users should not have to completely relearn how to interact with your mobile website. If they do, the custom site for mobile is a failure.

Second, Google and Bing take usability and overall user experience into account with ranking. Slow loading websites can have lower PageRank and a much higher bounce rate. Slow sites struggle to earn natural links, and users won’t wait very long to view a page on a smartphone.

These can serve as reasonable proxy metrics for your off page and on page success, respectively. A badly built custom mobile site can actually be a detriment to your online success. Keep in mind that load time is even more important on mobile than it is on traditional web browsers.

While I still advocate responsive design as a great solution for establishing a consistent user experience, either platform can deliver a good or great user experience. In other words, consider it a toss-up, assuming optimal management of either approach.

Learning Opportunities

Advantage: Tie / Neither

Future Forward Scalability

As you can already surmise from the above commentary, custom mobile websites take more time and effort to build and support. As you plan for the future, the logical assumption is that the website will grow and thrive over time.

Don’t just think about whether you have resources to build the initial website and assume that’s the whole story. You have to continually support updates, modifications and addition of new features. Can you really afford to put a full team in place to own two websites on two separate code bases?

Or even more importantly, do you really want to do so? Never underestimate the potential to grow a website. We have worked with companies of all sizes that made this mistake, only to end up with a tangled web of a site in the end. One tech company here in Austin recently underwent a major site design, and it took over a year just to figure out how to undo the mess they built over the years. Then they could actually think about how to rebuild it properly.

Did I mention this was on only one CMS-driven website? Double it and see if you think it’s still the right way to go.

Advantage: Responsive Design

What Google Advises You Should Do

Although I reached my own conclusion independently, Google recently announced on their web developers site that responsive is their recommended platform. See below for the exact verbiage from their site:

Overview of Google's recommendations:

Google recommends webmasters follow the industry best practice of using responsive web design, namely serving the same HTML for all devices and using only CSS media queries to decide the rendering on each device.

If responsive design is not the best option to serve your users, Google supports having your content being served using different HTML. The different HTML can be on the same URL or on different URLs, and Googlebot can handle both setups appropriately if you follow our recommendations.

So regardless of whether your team thinks they can support responsive or not, Google thinks they should figure out how to do it.

Conclusion: Responsive Wins!

There you have it. Responsive is more consistent for the user, provides a single platform for SEO efforts, and is much easier to build and support. Google gets this, which is why they advise to choose responsive over multiple sites.

We recommend that all of our clients do what we did with our own website, and build a responsive experience that you can support efficiently and responsibly, and it works like a charm.

Responsive is especially attractive if your site is based on a Web CMS. Themes are increasingly being built to be responsive “out of the box," and often at very attractive prices.

In other words, you may not have to pay a premium or even hire a dev team to support responsive if you use one of the leading content management systems. If your dev team insists on separate code bases, particularly if one of the two sites is in a CMS and the other is not, ask pointed questions about why they stand by that opinion.

Most technical barriers can be overcome rather easily with the right approach, so don’t just take their word for it. It is your site, so be sure to make the right decision up front if at all possible.

Title image courtesy of violetkaipa (Shutterstock)

Editor's Note: To read more from Tommy, see his Search Engine Optimization Trends to Watch in 2013