When I was in Thailand (1999-2002), I encountered numerous foreign guys looking for Thai wives or Thai women dreaming of finding foreign husbands. Granted that some of these Thai/foreign couples have wonderful and happy marriages, it was my observation that the majority of these marriage fell far short of what a marriage could and should be. First of all, the foreign guy usally speaks little to no Thai and the Thai women has little to no English. How can you know that you want to marry someone if you can hardly talk with them on a deep level? The answer is that you have low expectations for what you want out of marriage. As you can see from the article below (from "The Nation", one of Bangkok's English language newspapers), many Thai women see foreign husbands as an opportunity for financial security, greater social status. And the foreign guys are often seeking out a beautiful submissive Asian woman to cook, clean, and take care of their other "physical needs" (if you know what I mean).
On the plus side, foreign guys have a greater reputation for marital fidelity and not abusing their wives to their wives than do Thai men. This is a generalization, I know. I have known many Thai men who by all outward appearances love their wives very much, been faithful, and treatly them wonderfully. However, many Thai women have had the exact opposite experience and seek out foreign husbands in hopes of avoiding the abuse and heartache of their previous relationship(s).