It's hard to imagine that the company that makes a free game with an ad-free $1.99 version can sell for $180M. But that's what happened to OMGPOP, makers of Draw Something (see also the Draw Something Facebook page).
If you haven't played, it's a multi-player pictionary-style game with a big-button, friendly interface.
Using a basic set of drawing tools (four sizes of paintbrush, the same four sizes of eraser, and a small set of colours), a player draws their choice from three words, of varying difficulty. The process of drawing is recorded by the app, and then played back to the other player, so they can watch the drawing, and make a guess. Words are between 3 and 8 letters long, and you're given 12 letters to choose from - the correct letters are there, along with some decoy letters.
A successful guess adds to the number of "coins" the player has. Coins can be spent on two different things - a bigger range of colours, and more "bombs". The bombs can let you choose a new set of words (if the three choices are too hard to draw), or reduce the group of letters (to make the guessing easier).
There's a limited option for additional commerce within the game - you can spend real-world money on coins, or you can just keep playing and winning coins. Games never end: once you start a game, it just keeps going back and forth.
Games can be played against other users via username, or you can connect to Facebook and play against your Facebook friends. This creates a sense of reciprocity that makes it hard to escape - a friend has drawn a word for you, so you're obliged to guess, and then the game makes you draw another word.
It's hard to tell what the longevity of the game will be, but it is, for the most part, a fun undertaking in the short term. As the games build up, a sense of being overwhelmed with too many games to play can build up, but the simple solution is to delay your next game for a while.
What strikes me as new here is the video nature of the drawing: it makes what you're drawing more like an animation, and less like a static sketch being passed from one player to the other. This adds to the offline charm of the process.
Is there anything we can learn from "draw something"? Where we'd normally use text, we have to use an under-rehearsed skill - sketching. To get a single word across, you need to call on shared experiences, and metaphor. Drawing for someone you know well is much easier than for a casual acquaintance (or worse, a stranger on the internet).
It makes you consider the way someone will interpret what you're communicating, and distil an idea to its essence.
These are useful skills in communicating, worth trying to use whenever you're trying to explain yourself to someone.