Instructions:Been mailshot by Tesco with the following.
There is no mention of a minimum spend (have used it for a £20 order)
200 extra clubcard points when you order online between 08/01/2007 and 28/01/2007. (ive used it on an order of £20)
300 extra clubcard points valid on orders between 22/01/2007 and 11/02/2007
500 extra clubcard points valid between 5/02/2007 and 25/02/2007