I had mentioned in my July blog that I would revisit this topic again. A lot of companies are grappling with this at the moment and it can be quite confusing so hopefully this goes some way to helping with your decision making. According to statista.com, as of July 2014, Google accounted for 88% of the market share of the 4 leading search engines (Google, Yahoo, Bing, Baidu) so for the purposes of this article, lets assume your users will use this search engine to find your site.
1. Is my site losing Google ranking for not being mobile optimized?
We need to dispel this myth once and for all - you are not losing ranking for simply not having a mobile optimized site. In June 2013 Google announced measures that appeared to indicate that webmasters would be penalised for not having their sites optimized for mobile but in fact what they aim to do is simply penalise mis-configuration etc. when viewing on mobile devices. The changes are more likely to affect mobile adapted sites rather than responsive and should have no direct impact on regular sites.
This is where the plot thickens however because although a non-optimized site is not losing ranking directly, it will eventually rank badly organically because it will have a higher mobile bounce rate. Bounce rate is the percentage of visitors to a site who leave rather than viewing others pages. You can easily get an idea of your own sites bounce rate from your analytic data. If your bounce rate is high for mobile, it is time to get the ball rolling on optimization.
My own site is a very good example of this. I mentioned in my July blog that if your analytic data does not reveal that you need to upgrade then don't rush in. My own site analytic data indicated that I had a very small minority of visitors accessing the site through a mobile device so I was not in a hurry to launch an optimized version. When I examined the figures in more detail however I discovered that my mobile bounce rate was twice my desktop rate. So clearly visitors to my site were simply leaving when viewing on a mobile device and probably making a decision to only view it on a desktop. My new mobile optimized site is in place now and my mobile bounce rate halved in the first week after launch. Its clear that if for instance, an online shop is not configured for mobile, users will choose to avoid it. Recent data suggest that in many cases online shoppers do not check-out on a mobile device but they do the majority of their browsing there in advance of a purchase. So you could be losing business to a competitor merely because you have not adapted your site to suit the modern online shopping experience.
2. Should I use responsive or adaptive design and whats the difference?
Google recommend responsive design and it is easier to meet their mobile search ranking criteria using this method over adaptive. I have explained the principles of responsive design in my July blog. The difference between the two is that adaptive is essentially a new site (eg. m.example.com) built specifically for mobile whereas responsive adapts to all browser windows (minimize your own browser window to check this). For this reason responsive design is more cost effective and easier to manage your SEO (managed under one domain). Obviously responsive is not the answer to all projects and there is still very much a place for adaptive design. In most cases however, readers of this article will currently have a 'desktop' site and simply want it to function properly on mobile devices so for this I would strongly recommend responsive.
3. Is there a quick fix solution for mobile optimization?
In short, no! Depending on the age of your existing framework an upgrade may be possible but the optimization still has to be thought through and tested fully and various devices. Chrome Mobile Emulator is an excellent tool for testing purposes but there is no substitute for definitive testing on an actual tangible device. In the vast majority of cases though a rebuild will be the easier solution. It allows for development beginning with mobile first as explained in my July blog.