It’s an art, though, to balance the subtle placement and function of magical details against the need for user discovery.

For instance, if the Office Assistant was zooming out, jiggling and explaining every nuance of the mini-toolbar the first few times it appeared, that would be infuriating enough to make me never use it again, almost.

Conversely, I never knew I could drag the WordPress edit box to make it larger (so thanks!) I’ve been a WordPress user for a long time and wish I’d known about it a bit sooner.

The effectiveness of Apple’s magic discovery seems to vary according to age – younger people find it easier to discover the magic tricks by themselves, older people seem to need a little help. It might be related to the race memory of fear-of-experimenting that older computer users have as a result of decades using PCs that don’t tolerate experimentation well.

At the other end of the scale, I love Skitch to bits, but feel I’ve had to work a bit harder than really necessary to discover not just the magic, but even some of what should be obvious to the casual user. The Plasq crew try to help by popping up context-sensitive bubbles all over the place. But bubbles pop and unpop too quickly for many users and they can get frustrated with having to do so much searching for ‘hidden’ UI.

Lots of context-sensitive help in your product can be a sign that maybe your interface is too clever. No love in the social sphere for your product is a sure sign that it’s not clever enough. Fierce, undying love for your product in the face of competitors, discounting, more features – that’s a sign that you have the magic just right…

…or that you own the OS!