The basis of the top-down design method is to create a desktop display product and then find ways to smash that content into smaller screens. During this process, most of the time, you often overload the smaller device screen real estate with far too much information causing the smaller devices to slow down as well as making some the information not usable at all.
One study found, 71% of mobile users expect mobile sites to load as fast, if not faster, than that of their desktop experience to a site given the perception that the “mobile version” should be smaller in stature than it’s desktop counterparts. The same study notes that 74% of the mobile users will abandon a site that is loading, should the page be taking any longer than five seconds.
By developing in the standard top-down process, you risk severely limiting your incoming traffic from mobile users.
Besides the slowdown in performance, when you develop for desktops first, several of the functions and features you can do with a mobile phone are omiited from the usability thought process. With GPS, phones, voice input, etc., the mobile first design allows you to take advantage of all of these capabilities and implement them in your design. If you aren’t staying ahead of the curve, you better plan that you’re going to be falling further behind.
When you use a “Bottom-up”, Mobile First design process, you can build highly adaptive, future-friendly sites. This “progressive enhancement” help keep the content and media on a site from being way too heavy for the low tech phones to handle. If you take in to account that you are developing for the lowest common denominator, you can keep all your users satisfied and navigating throughout the site without the complications from those pages that are geared for more media rich. If we start with the most simplistic core foundation of a site and progressively add features to each level of screen dimension (and often processing power), etc. the process to do so is much easier as well as providing a much better base for future scaling.
Besides all of the technical advantages, from a design perspective, a mobile first philosophy helps us develop for ease of usability. With around 80% of the screen size taken away when you start with a mobile first design, you have to think about how to utilize your space in a much more efficient manner. This helps in keeping the core information you want to present to the users in the forefront without flooding with filler content to build out a large page. Then, as you progressively enhance for larger and larger devices, screens, etc. it helps keep you focused on the core values of your site and what the user can accomplish when visiting.
By the year 2014, mobile web users will overtake fixed web access (aka desktop pc usage). If that statement doesn’t give any evidence about the increasing need for a mobile first design, how about this one: the percentage of mobile web use increased (in just two years) in the US by 69%. And that’s just in the United States. Europe saw an increase of 183.43% and Asia saw an increase of 192.46%. Again, keep in mind this increase was just over two years.
The time’s, they are a changin’. If we don’t look forward, we get left behind