It used to be great then it became really hard to cash in your points for vouchers as they rarely had any in stock and then one day they stopped letting people buy vouchers.
I'm not really sure what you can do with your points now. I've got over 7000! I heard that if you donate your points to charity they don't actually get any money just the points which seems a bit pointless to me.
I don't even log in any more. I would use it again if they brought back the vouchers to buy.