Sports journalists love to hypothesize about the best athlete around which a new franchise could be built to win.

Let’s indulge a version of this exercise in business: if you were starting a company and needed a winning mobile strategy, what would it look like?

Would you prioritize building an app or a mobile website (or both)? Would you focus more on iOS or Android (or both)? Would you target the US or international markets (or both)?

This blog post is designed to help you think through these questions.

App or website?

A general rule of thumb others have evangelized and that I support is this: unless you’re convinced you can find enough users to pin your app to their phones’ or tablets’ home screens, you may want to avoid building one. Consumers gravitate toward the same 20-25 apps every month, making it very hard for a new app to break through.

Apps also tend to cost more to make than a website because publishers need distinct versions to support each operating system. In other words, you’d have to build at least two versions of the exact same app to work on both iPhones and Android devices.

When well made, mobile websites, on the other hand, tend to work on most browsers and require development skills that are more common (and, generally, less expensive) than app development.

It is true that data shows that users spend a majority of their mobile time in apps: 3 hrs. 5 min. in apps vs. 51 min. on mobile websites in 2015. Still, that’s misleading because of the number of apps that rely on mobile websites to work. A user may think she’s in an app when in fact she technically may be on a website that she accessed through that app.

Mobile sites also are getting faster and more responsive. Google recently announced a new open source initiative to encourage the creation of new mobile websites that will load much faster than current standards. That means tomorrow’s mobile web could deliver a user experience rivaling the speed and performance of apps.

In conclusion, build an app if it can crack your target consumer’s top 20 favorite apps or if you can’t build essential features via just a mobile website. If you go down this path and are building a consumer app, consider publishing that app when consumers tend to buy new phones, e.g. Christmas or after a new device launch.

iOS or Android?

As ubiquitous as the iPhone has become in the US, Android is the global volume king. In Q4 2015, Android captured over 80 percent of the share of new devices sold, compared to just over 17 percent for iOS. Nearly 1.7 billion devices now run Android. This compares to just over 1 billion for Apple.

Here again, though, the numbers can mislead. That’s because raw volume is just one important data point. Mobile strategists also must consider the size of unfragmented markets for these phones. For example, 77 percent of iOS users now run iOS 9, the latest version of the software.

By comparison, only 1.2 percent of Android users run the latest version, and more than half of all Android users run a version that’s one full generation older than that. The result: developers targeting Android must create several versions of the app just to work for the majority of those device owners. More versions means more cost and complexity.

Marketers also should consider the buying power iOS and Android users have. You can glean some of this from stats that show that since 2008, Apple has paid $40 billion to developers as a result of apps purchases and in-app purchases made on iPhones. Android’s economy may not surpass Apple’s until 2017, which is amazing considering the former’s significant device volume lead. The reason for the gap likely has a lot to do with the fact that iPhones tend to cost a lot more, meaning iPhone buyers can afford to buy more apps and in-app purchases.

Because of their premium price, iPhones tend to be more popular in developed markets. Android has taken off in emerging markets.

In conclusion, consider your target market’s geography/location and the total cost of developing for iOS and Android given their fragmentation (or lack thereof) when making your decision on which to prioritize.

Summary

Assume that in general, at least half of all our digital time spent is on a mobile device (compared to desktops or laptops). The trend is heading more toward mobile, which means that mobile will drive more of what we’ve traditionally done on other devices: shop, play, watch, listen and socialize. The latter is especially relevant for mobile: Facebook claims that more than 20 percent of all mobile time is spent just on Facebook and Instagram.

There’s no simple formula for when to make an app or a website the centerpiece of your mobile strategy, or whether to prioritize iOS or Android. Increasingly, though, it’s just about impossible to justify not having a mobile strategy in the first place.