Personalisation can be cheap. The visual one — the way things look (not to mix with the way things work and adapt to you — a whole different story). I’m bringing this up because many people in the industry believe it comes with a price and more often than not think of it in terms of full-blown “skinning”.
Back in the day skins were Big. Applied to Windows to make it look cool, to Winamp media player to match your music taste etc.
Problem was and still is very often that all applications immediately became inconsistent with the new skin and custom settings applied to the system. On top of that, giving too much control over content presentation resulted in users rendering things illegible, making your product look poor, not to mention development and testing time required to ship the kind of system that allows rich customisation.
Well, guess what — you can make mass production stuff feel personal. iPhone can come with a personalised engraving. And a limitless number of cases that allows you to choose not only how the product looks, but also feels in your hand. Of course, you can set the wallpaper, personalise ringtones… Small but powerful features.
All these personalisation options were fast and cheap to design and develop. But the final product look is changed dramatically.
All good visuals personalisation comes down to is striking that minimum set, that would enable people to connect with your product on a personal level. Not spend a ton of time to pick font sizes and setup colour schemes.