I always spray fragrance on my hair (worn in a chin-length bob). It does last much longer that way, and also diffuses better and gives more sillage. I also get a different effect than when I spray it on skin, probably because the composition evaporates more slowly and because it comes from a different distance than when I smell my wrist.
And since I wash my hair every day, it's better than spraying clothes, where the scent will stick around, sometimes even after a wash, and interfere with other scents I'm wearing.