About the first post...
I can say that this may work or not, as sometimes the less glamorous one isn't insecure, but exactly the opposite. Sometimes that one is the most secure with her looks, thatt's why she decides not to dress like the rest, but follow her own style. For example, sometimes the less glamorous one can be the one who already has a steady boyfriend and isn't interested in finding guys (why can't a girl with a boyfriend go to a club with her friends?) or is just one who is looking for a steady relationship, as Nanashi said, but is smart enough to know that sex in the first date won't usually lead you to that.
Of course, in most cases it will work, specially in USA, as it is very common to find insecure girls that wish they could be the most popular, the "high-school cheerleader", and those are often ready to give themselves fully to anyone who pays attention to them, and therefore will fall in this game. As this is pretty common (not in my country, though, as mine has a similar but different way of dealing with this) you will almost surely score wth that trick.
In case you want a long-lasting relationship, if you act correctly this could even be the first step to achieve that, as you will ahve her on your hands, so she will most surely love you for what you are, and those girls are the most tender and sweet ones you will find, so it can be quite useful to achieve that.
BUT, what I don't agree with is exactly that:
I don't believe there is a girl who isn't pretty, but I DO think that some girls are jut "not pretty for someone in particular". If you don't have standards, that doesn't make you lonely, it just makes you
The male humans usually just think that sex is everything. They can't even be in a loving relationship without sex, no matter what the reason. They will go "hunting" at night just to get laid (Take into conideratiion that I'm a man myself, and that I'm not gay, I even have a steady girlfriend). They can't feel love because they're too focused in sex, if you tell them that you love your girlfriend, you don't care about sex, and tht you give her presents, hugs and kisses all the time, they will think (and say) that you are gay. Most men don't understand that sex isn't the main target of a relationship. Sex is just a way, a way of showing love by "giving yourselves fully to each other", in an act that only cares about pleasing and making the other person happy, while enjoying therselves; an act of full pleasure where the ost important thing isn't the sex itself, but the person you are sharing it with.
I' not saying that it's wrong to go and have sex with someone you don't know, as everyone has physical needs, as well as emotional. I'm just saying that emotional needs shouldnt be left aside, they should be respected as well...
And, about the "cheerleader complex", I mean, the girls who just want to be popular. I believe that they are wrong as well. They may have their justification , as impopularity often comes along with emotional or mental problems, but I don't think that changing themselves to fit in is just the solution. "Fit in" isn't the solution, I think. The right way to do things would be to find someone who cares about you just as you are, and that's not that difficult, if you know how to look. The best solution is to have enough personal integrity to know that you will just be hurt if you try to just "go with the pack". This is because, n general, impopularity is created from "being different", but being different isnt always bad. If you start to act just like everyone else, you will get nowhere. Have you ever seen any parody films? Many times they just laugh at that, at the fact that everyone just follows the flow. Just have some integrity, and you will find the good way out...
I know this is harder than it sounds, as it always feels good to fit in, but you wil probably have to find some other way of fitting in... And, as I said, this is justified, because impopularity often comes with emotional and/Uor mental problems...
Im sorry if I just criticise everything, it's just my point of view... I will make clear that my grlfriend is different than most people (even has DID, among some other unbelievable differences

) but she has found the way to stay as herself, not just be like the rest.