Great topic, Thierry! I think most women appreciate the classy French/International design style posters, but not so much the typical guy stuff that fuels the hobby--Star Wars, Indiana Jones, Star Trek, etc.
But also, I think women are happy to buy just one poster. They don't have that insatiable need like most collectors! That said, I think this could be the way to expand the hobby, by somehow broadening the net and appealing more to women and fashion/art/design fans.