If your entry is good enough you can get two ticks instead of one. But do not get too greedy as "adding to" your trade after it touches your exit without filling sucks. ES
I always liked this statement - "If you can't make one good trade a day what makes you think you can make two?" I guess in the current context it would be - "If you can't make 1 tick a day what makes you think you can make two?" Law of large numbers aside
What kind of stop loss do you use if you're going for 1 tick? Even with no commissions, you're still only looking at about 10 bucks a win.