Re: Not a chance this will work out for Tesco
I think you're 2nd point is a load of BS. Club card is entirely to make sure you always shop at Tesco not at competitors. They wouldn't put all those deals together for 4X voucher value if getting you to spend the vouchers in-store was their main gambit.
Rather they are much cleverer, and get people hooked to using vouchers as the foundation for their dining out... always buy Tesco 'cos it means we get to eat out for free.
And I'm not sure your first point is much cop either. Amazon is a massive hit in the UK, as is Tesco itself outside the traditional groceries.