The growth of mobile devices (smartphones and tablets) cannot be stopped.

In the second quarter of 2013, IDC reported that mobile phones had reached 432 million units and tablets 52 million units, which represents 65% growth. At the time, PC shipments had declined by 11%.

If this pace continues, tablets will outstrip PC shipments in 2015!

Mobile hardware with smaller screens now represents 17% of all Web traffic (12% six months ago).

Media and e-commerce companies and brands have to hurry if they don’t want to miss the connection to this active and consumption-oriented target group.

But the question now more than ever is: Should we invest in one app or two to four apps for different operating systems in a mobile Web site optimisation?

The battle between app and mobile Web evangelists is always raging. Design vs. speed; perfect OS fit vs. all-device availability; permanent device integrated vs. use on-demand; island solution vs. Web-tracked.

Is the battle between these two products really a battle of substitutes, or are they not more complementary in the mobile world?

Mobile tech company Netbiscuits is running a survey in which 5,000 consumers are being interviewed across 10 countries (Netbiscuists People’s Web Report). The latest result: A user who is using a mobile Web site will not be open to installing an app of the same product.

From my perspective, this comes as no surprise. App and mobile Web usage are totally different. We are confonted with two different marketplaces. This makes the investment and product development strategy more difficult.

Mostly, your company needs to be represented in both/every marketplace.

The only important issue is: What percentage of my target group is using app store A or B? And how could I benefit from the complementary behaviour of a mobile Web site and app? Is there a chance to establish secure data in an app and also enjoy the dynamic content and e-commerce of a mobile Web site?

We all have to think more about the power of complementaries!