Mark Bridge writes:

Never mind customer loyalty, if you don't have an Apple iPhone you're a second-class consumer. That's the message I seem to have received from Nectar, the multi-retailer loyalty card company.

They've just sent me an email with a headline that reads "Exclusive bonus points offers at your fingertips". It goes on to say "Get the handy new Nectar app FREE on your iPhone or iPod Touch and receive exclusive bonus points offers at Sainsbury’s, Homebase, BP and many more great brands."

Apparently the app's been available for a few weeks, although I hadn't noticed because – oh, the shame – I don't have an iOS device. Therefore I won't be receiving the "exclusive bonus offers only available on the app". That's right, special offers only available if you have a particular type of mobile phone or music player.

Now, I realise that the idea of Nectar is to persuade you to alter your shopping habits in order to favour participating retailers. Visit Sainsbury's. Buy petrol from BP. Redecorate with Homebase.

There's even an internet search toolbar for Internet Explorer and Firefox. Which, unlike the iPhone app, is available to the majority of Nectar card users. The app is simply one step too far.

Rewarding a fragment of your customer base is no way to please the others. So please, please, can we call an end to this i-obsession?  I know I'm not the first to ask – Steve Dobson has warned against being "Apple happy", Tomi Ahonen has spoken of "App Store hysteria" and Martin Wilson diagnosed "iSyndrome". But this time it's personal.

If I want my loyalty card on my mobile phone, I'll trust Cardmobili. I'm certainly no longer a fan of Nectar. Because, for a company that talks about loyalty, Nectar has an odd way of rewarding it.