It's pointless everyone arguing about the "Are You Single?" approach. It definitely works, however there is so much to it.
If you listen to David DeAngelo who originated this opener. You will realize that an opener is only 7% what you say, and 93% of all the other stuff. You have to take into account different things like:
1. Your body language.
2. Your breathing(Is your heart beating 140bpms)
3. Facial Expression, are you smiling, deadpan, flushed, etc.
4. Eye Contact, are you looking directly in her eyes when you say that?
5. Delivery of the line. Hard to show this online. But, imagine the difference between rushing through the line, "Are you Single?", versus speaking it slowly with authority.
6. Timing, if you approach her in a bookstore, how centered is she in the moment. She might be still thinking about what she was reading, rather than giving you 100% of her attention.
When I played around with this opener, I had it scripted out as well. Find a way to continue the conversation, because you never know. For instance off the top of my head, here is what I might come up with.
Me: Hi, can I ask you a quick question?
Her: Ummm.... sure.
Me: Are you single?
Her: No!
Me: Cool, so you have experience with relationships. I just started dating this girl casually a month or so ago, and it's her birthday. Normally I would ask my sister for advice, but do you have any suggestions for someone that I've just started dating that isn't exclusive?
1,000 different directions that conversation can go. And it's better than just ejecting in my opinion. I have found that the Are You Single, doesn't work on about 1/2 of the women, and if you keep talking to them, they will admit they lied when they said No.
Anyway, the whole point of my post is that there are so many other aspects to the approach than just the words coming out of your mouth. And as someone else suggested, you're not going to have success until you've delivered it enough times. One approach isn't a track record. Heck even 100 approaches isn't a record. Try, try again.
Just get the words out for the first 10-20 times, don't worry about your results. And eventually start fine tuning all the little things that you can.
HTH,
--Romeo