spending over $250, you'll know you're in their system because you'll get a thank you note card.
There have been several discussions on this on the board regarding this topic. There are several of us who have made purchases over $250 and not gotten thank you notes. And who have made purchases for less than $250 and GOTTEN them. Official policy may be you get them at $250...but several stores/SAs seem not to follow the official policy.