I agree, it's the very first initial first glance that makes the rest more likely. If someone is not in the least attractive to another, they may never get a chance.
Interesting aspect to it. When I first saw my present husband, he was not the least be physically appealing to me.. looks wise. He wasn't someone I would have looked twice at in the past.. However, because of life circumstances.. (being widowed just 6 months prior) I was not looking for romance.. I was looking for a friend. AND since he had been widowed just 6 days prior to me, we were in the exact same place emotionally. So we became each other's sounding boards and confidants.. I had ZERO plans of him becoming anything more.. However, as time went on I found that I missed him when he wasn't around, and now we have been married almost 12 years.
My point in this little story is that if it weren't for the extenuating circumstances of being in able to get to know the PERSON inside.. and not just the outside veneer, we probably would not be together now. So yes.. I think looks are a big factor in the decisions people make... and perhaps this is the reason so many marriages don't make it.