Mobile device users still make up a minority of online customers, but it’s a rapidly growing market with tens of billions of dollars up for grabs. As such, when designing a website, companies should consider implementing adaptive design features that make their sites just as beautiful on a mobile device as they are on a computer screen.

The site UserZoom recently cited a study showing 61 percent of mobile users said that if a site performed poorly, they’d be less likely to visit in the future. It really is a one-shot game. Before addressing its mobile offering, clothes retailer Beyond The Rack found that 42 percent of people who visited the site using a smartphone left before even clicking through to a second page.

According to Internet Retailer, Beyond The Rack worked with a mobile specialist to make key changes to the site in order to make it smartphone friendly, including using HTML5 to ensure visually impressive but mobile-compatible design, automatically displaying an appropriate keypad when a user was presented with a field requiring a number or email account and cutting the purchase and checkout process for registered users to just three button clicks. The changes helped quadruple sales on smartphones.

So is mobile optimization really worth it?

Well based on estimates from comScore, in the first six months of 2013, total online sales to mobile users were $10.6 billion, up 27.7 percent from the previous year. That pattern is expected to continue at roughly twice the growth rate of sales among traditional computer users, meaning mobile will become an increasingly important slice of the pie. Already nearly one in six dollars spent online on event tickets comes from a mobile user.

Remember too that a mobile-optimized site isn’t just the difference between keeping and losing a customer. Google pays close attention to how long people spend on your site and how many pages they visit. The more people who are unsatisfied by their experience, the harder it is to get a visible slot in the rankings.

Google’s Hummingbird algorithm update, introduced in late 2013 was one of the biggest changes in Google’s ranking policy in a decade, and it’s particularly relevant to mobile users who have little patience for irrelevant results and don’t always construct clear and coherent queries. The key to Hummingbird is that Google now looks at every word in a query to try to decipher meaning and context: in other words, what a user means rather than simply the words they type.

That means websites are now rewarded for providing genuinely useful content that meets a user’s needs, rather than merely winning a guessing game to stuff a page with the right keywords. In particular, Google wants to users to be directed to the most useful page on your site for the visitor, rather than routing them through homepages. To take advantage of this, consider more customized, page-specific meta content rather than reusing stock wording.