Mistake #1

Take a look at this rather charming advert on the Guardian's mobile site. The more astute among you will recognise the problem. I'm being advertised an iPhone game when I'm browsing the site using an Android phone. This is the fault of the Guardian - or, more likely, whoever runs their advertising department.

Well, let's click on it.

Mistake #2

The image expansion doesn't work. This is probably because it uses iPhone specific code.

Mistake #3

Let's take a look at the raw image. The image is a 135KB PNG. That's massive. At a time when unlimited downloads are under threat, it is incumbent on the mobile web designer to minimise needless data usage.

If we convert the image to a JPG, the size goes down to 26KB. Can you spot the difference in quality?

Mistake #4

What happens if we visit the destination? Ah. Apple send us to the desktop version of iTunes. This is better than what used to happen, where they tried to install iTunes!

Preventing The Problem

Every browser sends a User-Agent String. The advertising server should be configured to only send iPhone-specific adverts to iPhones.

It really is that simple. You can use services like WURFL and DeviceAtlas to automate this process if you like.

What Should Have Happened

• The advert shouldn't have been shown in the first place. The Guardian needs to ensure that the advertising space it is selling is being correctly targeted.
• The click should have gone directly to Barclays - if they saw the phone viewing the content wasn't an iPhone they should display alternate content.
• Apple needs to have a mobile friendly page. It really is that simple. A great mobile friendly page with a link that says "Want to play this games? Find your nearest Apple Store here".