I agree that the majority of

I agree that the majority of people who marry do so for non-monetary reasons. I do believe, however, certain individuals likely marry into certain groups for monetary gain - such as marrying a professional athlete. Although Bella's book does point out the plethora of financial incentives that are showered primarily upon married couples.

But I think most the rest of individuals who marry do so under the irrational spell of matrimania - the societal belief that someone is not "complete" unless and until a marriage ring is on one's finger and have a white picket fence to go home to each evening.