I/O ARM 3-1 Mortgages the Norm?

I was looking through the real estate catalogs you get outside of Shoprite or 7-11 and noticed that some houses are advertised with an estimated monthly payment amount. This is has been a standard adverting gimmick for a few years as far as I can tell. However, I also just noticed that the estimated monthly payment is no longer calculated on a straight 30 year fixed rate mortgage basis. Instead, the payments are calculated using the newer exotic mortgages. In the catalog I saw this weekend, the realtor doing the advertising used an interest only ARM according to the tiny print in the disclosure statement at the bottom of the page. I bet a lot of people don’t bother reading the disclosure statement in these catalogs.