In my store, of the general we sell I would say a majority, a significant majority is purchased by women. There seem to be, in the case of my store, popular titles for women but far fewer for men. I’d say the works of Maeve Binchy, Cecelia Ahern, Marian Keyes and their ilk account for something over 50% of general purchases made. So bookstore dopers have you noticed any signficant gender bias in sales?
I don’t work in a store currently but I used to, and I agree that whilst there is chic-lit there isn’t any equivalent man-lit. I think men tend to read more from crime and biographies, but YMMV.
True crime, sports and political biographies and any number of other things are popular with men but I still get the impression I sell way more books to women. Reading books doesn’t seem to be as nearly a popular pursuit amongst men as amongst women but I know I have a paltry sample set!
I recall watching Oprah Winfrey’s show one day when she was having one of her read-fests which involved video of five or six women at her (Oprah’s) home, discussing some book they had all just read. Someone in the audience raised their hand and asked Oprah if she had thought about starting a reading club for men too. Oprah chuckled and said somehow she just couldn’t see a group of men sitting around in a room together talking about a book they had just read. 
I’m former bookshop manager (and could be one again depending on how things go!).
I don’t have a specific cite for you but I have seen plenty of statistics over the years. It is a pretty established fact that women consume more books than men, so your impression is correct. If you want to sell lots of books then aim at them.
My husband is in a book club that has been going for decades. (He’s been in it about 10 years). The members include lawyers, judges, research scientists and other professionals. They read widely, including biographies and history, but also novels. The last book, IIRC, was Gorky Park.