Gail, the promotional discount deals do require a sales tour. If you look at the DVC website at the descriptions of the discounted rooms and scroll down to the bottom, you'll see a part (in the eligibility section) that says this (or something similar):
"In order to take advantage of this offer, attendance at a 90-minute sales presentation is required, or the full retail value of the package will be charged (up to $230 per night plus state and local taxes). If married, both husband and wife are required to attend the sales presentation together."
That's from the $99 promo at DVC HHI.