Inspiration or desperation? Whatever the motivation, Microsoft seems to be kicking its OneDrive campaign into high gear. Last week, it dangled the carrot of 100 GB of free cloud storage for two years in order to get people to sign up for Bing Rewards. This time, it's making a slightly different offer to entice Dropbox users to make the switch. And this time, for those who were irked by the limitations of the previous offer, the free space is available for anyone in the world to claim.