Speed is a feature: Why a slow mobile web experience means lost revenue
Jasper Jackson @ - on 2/10/12
There's no point creating a beautiful mobile web experience if it takes so long to load your audience never sees it.
It's an important point that gets overlooked but it was rammed home in a presentation by Craig Sullivan, group business manager at Autoglass owner Belron, at the Mobile Marketing Live event on Monday. Here are his slides, followed by more of his talk and our analysis:
Sullivan says the mobile sites of leading brands are seeing load times as long as 10 or 15 seconds, when really loading up a mobile site should take two seconds at most. He took a quick look at some top brand mobile sites and measured the amount of data downloaded to a mobile browser, and how many times they requested a file to load the page - both good indicators of how long a page will take to load.
Whilst preserving the identity of the worst offenders, he found a "leading high street retailer" trying to deliver 307Kb of data, requiring 43 different requests or separate attempts to download information. Even worse, he found a national newspaper trying to push through 195Kb of data to a handset, requiring 35 requests.
As Sullivan says, trying to deliver that amount of data over a 3G mobile network can be like "trying to shove a pig down a toilet using a Twiglet".
His company's own Autoglass mobile app only 25Kb to a user's handset, and needs just 10 requests.
Lose seconds, gain users
Why is this so important? Because seconds waiting means lost users, and ultimately lost revenue.
Sullivan cited stats from web optimisation firm Stangeloop, which in November last year tested the impact of different delays by inserting an artificial delay into the load times for the users of a site run by one of their clients.
Strangeloop found a one-second delay led to a 9.4 percent fall in page views and a 3.5 percent fall in conversions. The delay even affected the amount users spent on the site - reducing checkout cart size by 2.1 percent. Even smaller delays of 500 milliseconds had a negative impact on page views and conversion rates.
We heard recently how cloud music service Spotify's goal is for music to start playing 0.6 seconds after a user presses play - anything more can result in complaints.
And here, shown in this handy graph, is perhaps the most worrying thing they found - the second delay had a huge impact on whether visitors would return to the site, even weeks after the delay was removed.
What can you do about it? Here are a selection of Sullivan's key pointers.
-- Keep file sizes and requests down: Keeping down the number of requests a browser has to make, and reducing the total amount of data delivered will, shockingly, reduce the amount of time needed to load a page. A beautifully designed mobile site may help build and keep your audience, but if that means delivering a lot of data that bungs up a mobile web browser - you will also lose some of that audience.
-- Test your site with real handsets: Make sure you measure your mobile site's performance on a wide range of real mobile handsets running on mobile connections, not Wi-Fi.
-- Use content delivery networks: For international audiences, it is important to use content delivery networks such as Akamai to ensure your data is stored nearer a user to keep delivery times down.
Keeping your mobile site fast could be the difference between gaining a new customer or having them never see your site in the first place.