I don't know if this the right place to ask this.

Do you mean long term data storage? with any backup medium, it is suggested to make more than one backup for important data. some have suggested than ideally cards should be placed in a device or reader that is then turned on at least once every 6 months to reenergize the card. I don’t know how necessary this is, and how likely a problem with the data becomes if the card isn’t energized for a few years. I would also like to see data on card errors comparing micro cards to full size cards. Are micro cards and full sized cards cards by the same manufacturer with the same capacity and the same data rates equally reliable, or are full sized cards perhaps more reliable? I read articles that reliability depends on the number of bits per cell, and that  expensive cards with just one bit per cell are the most reliable, and will last for the longest number of write cycles. 

https://en.wikipedia.org/wiki/Multi-level_cell