Francisco d'Anconia said:
Too many guys depend on negging because they're lacking in other areas. Negging isn't necessary in a normal pickup.
I agree, but there are a lot of times negging can make your life a hell of a lot easier. I only really resort to negging in situations where I have low social proof.
For example, I was out with a group of friends I don't know very well this past weekend. They all act very clique-ish (almost like high school), and many of the hotter girls congregate together and only talk with a select group of the guys (again, almost like high school). As an outsider, it was tough to hang out with them and get any of the "hot" group of girls to pay attention me.
Now, I'm a good looking guy and I feel like I have a lot of game but it was still hard to work my way into that group of girls. At one point, I was sitting by all of them and they were barely even acknowledging me, even though I was trying to add to their conversation. I got up and said very loudly "Right, looks like I'm not cool enough to sit with you guys".
A light neg, but it still got a rise out of all of them. They apologized saying that their group of friends had a bad tendency to be clique-ish with each other.
I do agree that negs are something that should be avoided, but there are cases where they can really help you out. In instances where your social proof is very low, a neg can save you a lot of work.