Do men or women shop with us more? And who is actually who? Figuring this out isn't exactly easy. Unless, of course, you have a handy database...
I deal with gender determination issues for almost every one of my clients. Over time, I've created my own database of first names from all over the world, along with their gender. It's not always possible, there are many "unisex" names, but for the rest, I have a relatively high success rate. So if you have data with first names and want to assign gender to them, you can reach for my repository on GitHub. You'll find almost 70,000 names from around the world in CSV format there.