Ok, let's pretend for a moment that I would be the least bit interested in this girly crap, here are my thoughts...
www.birchbox.com: By the pic on their site, it appears that they have a larger selection of products that are more popular. This is a good sign. One thing you don't want to do is buy a bunch of crap for your lady that she's never heard of before. Plus, when it comes to cosmetics, some products can make skin break out. I've learned that this usually happens w/ off-brand cosmetics.
I like this site as well. A lot of stuff to choose from, etc.
www.myglam.com: I wasn't impressed w/ the website at all. They displayed a pic w/ only a few items showing. My guess is they have a bunch of crappy off-brand cosmetics and such.
This site seems like it would be for the make-up impaired female. How-to videos on how to apply their products? If they need instructional videos, then this probably isn't the type of stuff they want.
www.ecoemi.com: Holy hippie hell, Batman!! Eco-friendly girly crap? Seriously? I just glanced at their site for a split-second, but now I have a deep desire to throw on some Covergirl and run outside and chop down a tree.
As I mentioned already, I do know a female who would be totally into stuff like this. If you've got a green-friendly woman who looks for natural ingredients, etc., then she might actually like this. If not, I wouldn't waste my time researching this site.
As far as my overall view on getting this crap for your lady friend... go with your gut feeling. If your gf/wife likes this type of stuff, you should be fine. However, if they don't, it would more than likely be a waste of money. I mean sure, she'll smile, say, "aw, how sweet", but then you will find the crap collecting dust on a shelf.
This.