To be fair, any backup service should probably best have model of "pay per length of backup stored". If I want to store my 100GB of data now, and I want to hav

To be fair, any backup service should probably best have model of "pay per length of backup stored". If I want to store my 100GB of data now, and I want to have it stored for a year, I want to pay for that year's worth of storage of 100GB of data now and not worry about any money or account problems for that bit of data.