If you lead a horse to water, show him how to drink
What is this 'app store' thing that takes me to some obscure page when I click it and then tries to open some desktop application that I don't even have installed? I've never even plugged my phone into my computer once - I didn't know I was supposed to.
Developers - non-technical people don't understand the app download process. Make it easy. After clicking that button, explain how the user can download the app with bullet points and pictures.
Option one: Via iTunes/Google Play/Zune on your computer. Don't forget to show them how to download the desktop software as well.
Option two: Via the app store icon on their phone. Give step-by-step instructions. Show them what term to search for. Remind them how to find/reset their Apple ID and set payments up as well.
Bonus option: Enter phone number to send download link.
In my observations there are large numbers non-technical people who own an iPhone/Android/WP8 who can afford the monthly cell and data fees. These people have buckets of money to spend - but - they have no clue how to download an app. Take a look at their phones - they haven't downloaded a single app. Make it easy for these people, please.