because giffgaff don't do contracts.. we are never tied in to stay with giffgaff.. and free to leave whenever we want
also, we are free to choose whichever goodybag we want/ need each month.. or not buy a goodybag at all..
giffgaff.. already gives us so much flexibility to fine-tune our mobile plan (i.e. goodybags) to suit our needs each month.. so there's no need to overspend on a goodybag with data allowance that's more than needed..
hence, no point in rolling over data..
we as customers have total control over our usage.. unlike other networks.. where we are locked into same plan for at least 12 months.. regardless of our usage fluctuating month to month
bottom line is 'i choose giffgaff'