To promote Safer Internet Day 2016, Google is offering 2GB of free storage space on Google Drive to anyone who reviews their account security settings.
Reviewing your account settings involve confirming the recovery phone number and email ID, confirming the devices connected to your Gmail account, account permissions, app passwords and 2-step authentication settings.
Once you are done confirming your account security settings, Google will automatically add 2GB of space to your Google Drive account. Keep in mind that the 2GB of space added to your Drive will also reflect in Google Photos storage, which will likely be handy for many people.
You can review your Google account security settings over here.