Contrary to many reviews I've read, I've always had good luck with Zulily. Each item has a size chart specific to the brand that they're selling (since they sell many different brands), which I found very helpful. You HAVE to look at the size charts, even for shoes! I've ordered all sorts of things from here over the past couple years - a coat, lingerie, shoes, a purse, and a dress, and the merchandise has always arrived well-packaged and mostly on-time.
I've only experienced their customer service once, but there was no issue. I had ordered a couple of bras through Zulily, and one of the colors was no longer in stock as they had thought, so they issued me an immediate refund, and the remaining bra was sent on time.
The only reason that I gave 4 stars instead of 5 is that they use a multitude of different shipping companies, some of which I've never heard of, and the items often don't all ship at once, making it tough to track orders. This is the nature of a website that sells merchandise from other companies though, I imagine, so it's not a dealbreaker.
Bottom Line: Yes, I would recommend this to a friend