Anytime a man looks into a woman's face, he notices three things (in no particular order); her eyes, nose and mouth. The cultured fellow, before venturing on to the mountains, fertile valley or hills, will take note of the young lady's eyebrows. They say that the eyes are the windows to the soul, but sometimes you learn a lot more about the house by looking at drapes than the view.
For instance, you are immediately aware of her natural hair color (or relatively close to it). Not that big of a deal, but worth noting. Next, you have a general idea of her opinions about grooming and fashion. And finally, it's potentially a barometer of sanity.
While only a select group of guys really care too much one way or the other about natural hair color (comments regarding carpets matching notwithstanding). But it does provide a tiny window into her vanity and level of requisite maintenance (them dye jobs is pricey, ya'll).
Not every guy necessarily has an eyebrow type but lots of guys do dig one shape over the other. He may like the small, slightly curved ones (like Mama), the arched jams (like Megan Fox) or the bushy jobbies (like Abe Vigoda). For instance, I do have a type; the arched brow. It looks slightly dangerous and mildly mysterious. Unfortunately, to my knowledge, it is the most time-consuming and whorish shape (though the slanted shape is neck-and-neck). Eyebrow styling has never been a deal-killer for me, but total lack of eyebrow regard has been. How much effort does it really take to turn a unibrow into two separate, divisible brows? If you think of your hair as an outfit for your head, please think of your eyebrows as an outfit for your eyes. If you want any hope of maintaining eye contact with all but the man with greatest willpower, you should provide a decent landing pad for his eyeballs. If you don't believe me about the importance of eyebrows, please check out HotChicksWithNoEyebrows.com (do so at your own risk and have a bag or bucket to vomit into handy).
And finally, while a woman's eyes may be more of a tip-off if she's slightly bonkers, her eyebrows run a close second. In fact, eyebrow over-grooming/ re-penciling may be the best, skin-deep way to tell if a woman is obsessive-compulsive. And some guys dig obsessive-compulsive but all guys like knowing what they're getting involved with.
In short, a gal's eyebrows typically say a lot more about her than her hairdo possibly could. Take a good long look in the mirror and make sure that your eye clothes say the right thing about you. And keep in mind that there are a bunch of options for cleaning up those eyebrows, you can shave, pluck, wax and, thanks to the Indians, thread those eye clothes into shape. Then feel free to browbeat the next style-conscious guy into submission.