Every marketer understands that the mobile channel is growing rapidly. By 2018 analysts estimate that there will be nearly 2.7bn smartphone users globally, a 250% growth since 2012.

Mobile devices are becoming the primary method of accessing the internet and digital media. Indeed, research from comScore found that 60% of time spent on digital media was through mobile devices. In contrast time spent on desktops has declined 20% over the last year.

This increased time on mobile devices is translating into major changes in the paid search landscape, meaning marketers have to change how they approach mobile.

In the past the focus was on ensuring a company had a responsively designed site and potentially an app to engage with customers. Key areas simply were not optimised – for example, research we carried out with

Yahoo found that only 15% of marketers tailored ad copy by device. This one size fits all approach treated mobile as an add-on to the ‘main’ desktop advertising programme, rather than recognising its importance.

Analysing our own data from Christmas 2014, here are three key reasons that marketers need to move to a mobile-first strategy:

1. Paid search revenue grew by 120% on mobile phones

With more consumers using their mobile devices in the buying process, last Christmas saw a dramatic increase in spending by retailers, and greatly improved conversion rates.

Spend on mobile phone advertising grew globally by 77%, driving a 120% increase in revenue. Mobile phone ads saw Click Through Rates (CTRs) increase by 45%, with impressions up by 79%.

Increases on tablets were smaller (spend up 6% and clicks 7% higher). However, metrics such as impressions and clicks were up across all mobile devices. This is in stark contrast to desktop, where impressions, clicks, spend and revenue were all down compared to 2013.

2. Mobile devices now responsible for nearly half of paid search clicks

Consumers are adopting a multi-device approach to shopping, with the majority of final paid search conversions taking place on desktops.

However, mobile has a key role to play in the customer journey, particularly during the research phase and when creating brand awareness.

Demonstrating this, the number of paid search clicks on mobile devices has grown, year-on-year, with a 45% increase on phones and 7% on tablets. In contrast desktop clicks decreased by 16%. This meant that nearly half (48%) of clicks now happen on mobile devices.

In EMEA the figure is slightly lower, but 34% of clicks (and 33% of spend) takes place through mobile.

3. The desktop/mobile gap is lessening

Despite the growth in mobile, desktop computers still drive the highest conversion rate (6.9%), compared to desktop (4.6%) and phone (2.1%).

However, the cost-per-click (CPC) gap is lessening, with mobile phone and tablet CPC catching up to that of desktop computers. Conversions on the phone grew by 225%, and 88% on the tablet, while dropping on the desktop by 18%.

Given that phone screen sizes are increasing, and that consumers are becoming more accustomed to completing transactions on mobile devices, it is likely that these gaps will erode further over 2015.

What next for marketers?

Now that mobile accounts for over half of the time people spend online, marketers need to move to a mobile-first advertising strategy that connects to other channels such as desktop and in-store.

This provides an opportunity to engage with consumers more often and influence purchase decisions. It goes without saying that you need to be sure to provide consistent, relevant messaging across all channels and create a seamless experience for the whole customer journey.

As planning begins for Christmas 2015, now is the time to work towards a mobile-first strategy.