Ah, oh. Once again you are talking commodity. Therein lies the rub. One big issue, imo, is the 'love' factor. I personally prefer to be attracted to and in love with my significant other. If someone can find a partner in a catalog or online that they are attracted to and fall in love with them. I personally see no problem in that. How often that can happen, who knows? Maybe we should all go shopping for our mate in a catalog then. ;)
I hesitate to join this smoldering flame-fest, but...
Your comment reflects the typical idea these days, but it seems like a recipe for divorce to me. What do you do when your significant other gets fat? Or bald? Or wrinkly? Physical attraction is temporary. If that's what keeps your significant other with you, then you can expect him to upgrade eventually (if he can afford to).
Nobody on this thread has mentioned arranged marriages yet, but they're solid evidence that impulse-pairings are not the only way to go.