Welcome to Player Attack!
If you've ever wanted to grab a new game, but didn't want to have to get off of the couch, Steam has come to your aid. Similarly, if you're captured by the new-game-desire while on a bus, in the bathroom or anywhere else that you take your smartphone.
A new feature has been added to the Steam beta client, which introduces a tidy new remote download management function. This means you'll be able to trigger a download on your PC (or Mac) Steam account, just by visiting the appropriate page on the Steam website using your smartphone browser. By "download" in this context, publisher Valve kinda means "buy", of course.
Want to check it out? Open up your current Steam client, go to File -> Settings, open the Account tab and click "Change". Select "Steam Beta Update" and restart the client.
Once that's done, we've got the handy instructions right here - more than enough to get you started! Now there's even less standing between you and those killer sales. Your wallet will never be the same.