Hi let me see if I can answer your question.
You should expect to see payments primarily for storing data and allowing customers to download (egress) data. Having more storage increases how much you get paid and the likelihood or more downloads. Storj has a hold back mechanism that retains some of your payments for a while to ensure that customer data is retained for long periods and not lost. You can run an earnings script to see the details. Your nodes ability to quickly respond to requests will affect whether you get data more quickly than others, so distance has an impact, however I am in the US and see decent traffic (I currently am holding about 12 TB of data with capacity for 35 TB total spread across three nodes. The first one was brought online in December 2019. My egress this month is around 700 GB so far.
Please go to this calculator (best to copy it to your own Google Docs account to modify it for your situation: