Here is an idea for all those big supermarket chains out there: as customers enter the store, give them an RFID tag to wear. That way, with the use of some strategically placed readers, customers could be tracked right across the store. Store managers could identify where people spend most of their time, what aisles are popular, what spots on a particular aisle people slow down at (there might be a promotional item at that spot). The possibilities for gathering useful data are endless.

So why don’t they do it? I’m pretty sure most people would give them a two-fingered salute and take their business elsewhere. Unless all the supermarkets did it at the same time and then we would have no choice.

When it comes to the web, it isn’t a person’s body movements a website owner wants to know about, it’s their mouse movements. After all, unless you are visually impaired, the mouse is the manner in which most users interact with a website, hovering over links, scrolling, clicking etc.

A new web service, ClickTale, has come up with a way of recording these actions so that website owners can record and later review, every mouse movement and scrolling action a user has made throughout a given website on which it’s service has been installed. I haven’t used the service but from what I’ve read and seen of the client side javascript it loads on a user’s page, it makes use of some AJAX wizardry.

Clearly, this is certainly a very useful tool from the website owner’s perspective, but I would members of the general public be so happy about it if they knew it was there?

It has some great applications in beta testing, usability testing and debugging of websites, but I wonder if it isn’t going just a bit too far for general use? Just because you can do something, doesn’t mean you should.

ClickTale do address privacy in their FAQ, I’m parphrasing here, but it boils down to “we aren’t gathering any personal information on you, so it’s ok”.

Lets translate that back into the real world: “If I follow you around town all day recording your every movement, but I don’t ask you your name, thats acceptable”.

I’m not so sure.

Like I said, ClickTale looks like a great service, and I wish the guys every success, but it points to an issue that is becoming more and more relevant in relation to the use of the web’s belle de jour, AJAX.

AJAX can be used to capture lots of information, from mouse movements to form inputs, without the end user knowing about it, or before they have pressed a submit button. Gone are the days when a user knew they had to hit the submit button before their info was processed by a website.

If we are going to be using more and more AJAX in our web applications, and I don’t see why we shouldn’t (I just spent the past 2 days working on something that uses AJAX), we had better make sure we don’t freak users out and have them switch off Javascript in their browsers.