Very basic question: I've received lots of free space through referrals and grants in the past, but I need to upgrade for a short amount of time as I need more space for the next month. When I'll downgrade in a few months, would you know if I still will keep the free space I've earned over the years?
Yes, the space you have earned will remain valid. Good news is: when you upgrade your referral bonus will double. Say you have 20 successful referrals, for free/basic account, you earned 500MB per referral, so 10GB increase. When you upgrade, the referral bonus is 1GB per referral, so your referral bonus will increase to 20GB. However, once you downgrade it will reduce to the same amount that you currently have as free account.