I knew an Italian dude that had a fake marriage in order to stay the US - he was a video game programmer making 100K+ in the early 90ies, but didn't have a college degree, so obviously wasn't qualified or some such tripe. He said that they are pretty thorough in their investigations of your marriage, especially if there are no kids.

If it were me in charge, the customs/immigration/etc folks would be the first ones up against the wall:-)