I know similar has been said by the other contributors before but the big problem with Nectar is there's no way for customers to grow attached to it, the benefits are so small that people just hand over their card because it's better than nothing but they don't feel a sense of loyalty to any of the brands that partner with Nectar. People have a Nectar card because they shop at Sainsbury's (or BP, etc) they don't shop at these places because of Nectar. This was shown particularly well last April when Sainsbury's halved the earning on the Nectar scheme and it hardly had any impact on sales. If people cared about Nectar they'd have all defected to Tesco at this point.
Thanks to the poor quality of Nectar a lot of people think all loyalty schemes are the same and in the long run we hope to prove to businesses that a good scheme such as East Coast Rewards can do to build loyalty. Imagine if Virgin Trains East Coast had taken the scheme, adapted it to suit their needs and then put their marketing resources on promoting that rather than Nectar they could have had an amazing success.
We need to keep trying to get the message out to businesses that loyalty schemes done right can make a difference and to consumers that not all loyalty schemes are as unrewarding as Nectar.