I got one too today. Below is the text of the email, as requested:
Date: Wed, 16 Apr 2008 12:25:06 -0400 (EDT)
From: "Full Tilt Poker Affiliate Team" <firstname.lastname@example.org>
Subject: Get Rakeback for Your Player Account
As a valued player on our site, we are pleased to inform you that you have been selected to receive rakeback on all of your future play at Full Tilt Poker.
Currently this opportunity is only available to a select group of loyal players that have played on our site without the ability to receive rakeback.
To take advantage of this special offer, visit www.rakebackpros.com
and sign up for an account.
If you have any questions, please contact email@example.com
The Affiliate Team at Full Tilt Poker