When a brand wants to increase its visibility, it buys print ads, TV spots and on-line ad banners. If you want to target women you'll chose magazines, TV shows and websites designed for women. This how the advertising world used to work. But this will change... at least on-line!
On the internet, there is data everywhere. You can measure how visible you are, what engagement you created with users. You can also measure who you served ads to.
Gender, age, revenue, degree, interest, belonging, purchase intent... so many things advertisers could know to measure the efficiency of their campaign.
But now these metrics can be used to optimize each ad sold, individually. If you want to target men, you'll probably try to advertise on sports sites or car sites. But there are also women on these sites! If you target men, ads served to women are a waste!