You always want what you can’t have — especially when it comes to beauty products. That’s why we’re getting the inside scoop from your favorite retailers on what’s selling out right now, how to sign up for wait lists, and where to go to find the next best thing. Because if everyone’s buying it, you know it’s got to be good.If eyes are the windows to the soul, brows are the curtains. And beauty-wise, combing, brushing, and filling your brows is about as simple as it gets for majorly impactful results. Good brows can anchor your face, define your eyes, and add emphasis to any makeup mastery you've got going on on your lids. Given the sheer popularity of fleek-worthy brows, we weren't surprised to learn on Glossier's Facebook that Boy Brow, which launched in October, had a 10,000-person waiting list until it was restocked in March. (Kelly Mittendorf, a public relations coordinator at Glossier, confirmed the stat for us via email.)The product keeps hairs in place without veering crispy like so many other formulas, but it also adds believable heft to sparse areas and leaves behind a wash of subtle pigment. (It comes in three versatile shades.) Since we started using it a few months ago, it's quickly become one of the easiest — and most rewarding — steps in our makeup routine.If you're looking to give this one a whirl, and given the brow wand's storied fame, we suggest you click " add to bag " sooner rather than later. But if you don't get a chance to buy it in time, we've also gathered five alternative brow-perfecting products for a groomed and glossy set. Check 'em out in the following slides.