Microsoft recently rolled-out an upgrade to free OneDrive accounts, but is only now sending out emails to its users to notify them of it. Previously, the company gave any new sign-up 7GB of storage for free; that's now been bumped to 15GB, to match Google with its Drive service. Both are a vast improvement over Dropbox, which offers a mere 2GB of free storage to its users, requiring referrals to increase it to a maximum of 18GB.
Because of Google's move to offer 15GB for free, I think this action was pretty-much required by Microsoft if it wanted to properly lure new users in. However, even 15GB is rather paltry compared to the 25GB free that the service originally gave. Maybe we'll get there again, some day.
Microsoft's decision to bump free accounts to 15GB comes hot on the heels of its decision to reward Office 365 subscribers with a staggering 1,000GB of cloud storage. As a subscriber, I admit I sure didn't mind hearing that news.
At this point, the free boost to 15GB of storage should reflect every OneDrive account. You can check your current storage total simply by visiting the OneDrive website, and looking at the bottom-left corner (like in the shot above).