the problem with infinity is that there is a lot of it

1024 x 800 = 819200

819200 is a big number.  Especially if you are only allowed to choose one.  Talk about analysis paralysis.  But in fact most computer users are confronted with this problem on a daily basis.  That number represents the number of pixels available on any modern computer.  Any time you initiate a drag and drop operation on your computer, you are faced with that many potential places to “drop”.  For some tasks this flexibility is necessary:  Modifying pictures in Photoshop.  Drawing that award winning webcomic.

Some tasks however don’t require infinitely flexibility.  You can see this when attempting to drag a file to the wrong place.  Try dragging an image from a website into your calculator.  It’s possible, but meaningless.  That’s because most of those 819200 choices are “wrong”.

There is nothing inherently wrong with building in support for drag and drop in your software, but don’t presume that users will encounter them.  We’ve had drag and drop interfaces commonly available for 20 years, and it’s still a novel approach for most users. I can do some cool things by using drag and drop.  I can quickly take a URL from safari and drop it into a blog post. That’s a nice shortcut that saves me some cutting and pasting, but if it was the only way to create links we wouldn’t have nearly so many of them.

If you write software, don’t presume that users will try any of the drag and drop operations available in your software without prompting.

If you are a user, try dragging some things and dropping them onto other things, you might be pleasantly surprised.