when I opened Microsoft's One-drive app on my android phone I came across the following:
Install Outlook app and get 100 GB for 2 years free.
The promotion also had link to click where it took me to Android Playstore for the Outlook app.
I installed the Outlook app and didn't configure anything in the outlook, but instead came back to the One-drive app and it refreshed automatically saying "Redeeming the offer.." adding 100 GB to my One-drive.
I guess it might be targeted. That's why a YMMV on the title.
Edit: Adding more information after some quick googling
- I'm guessing this promotion is more related to Samsung Galaxy Phone users but I might be wrong
- I redeemed this offer on my S7 edge. (Note, I had this phone for last 2 years and already redeemed this kinda offer before from Microsoft One-drive)
- This offer doesn't seem to "only linked to new galaxy phones". This promo can appear on your old galaxy phones as well.
The below steps might also work, You can also try
1. Sign out of all OneDrive bundled applications (Word, Excel, PowerPoint and OneDrive);
2. Go to 'settings', 'applications', then 'OneDrive', and 'Clear data' and 'Clear cache'.
Worked for me after relaunching OneDrive."
Source - https://answers.microsoft.com/en-us/onedrive/forum/ [microsoft.com]