I was looking at properties and rates earlier today and found a Westin being offered at 5K+$75 on the mobile app. I then went to the SPG.com site using my laptop and repeated the search, this time the same property and date showed the Cash&Points as 5K+$100. Went back to the app (redid the search) and found the same 5K+$75.

Can anyone explain why the app gave a lower rate than the regular web site? All the other cash rates were similar on both platforms.