http://systembytodd.com
When you talk to a girl. She's sizing you up. Are you confident or timid? Do you have friends and good social reception? Do you know what you're doing with girls? Are you successful? Are you "cool"? Some of these things she figures out over time, but many of them she knows almost INSTANTLY based on specific behaviors that are "honest signals" of your value as a man. If you get these behaviors wrong, you're not going to get girls above a certain calibre... if you get them right... let's just say, you really want to get them right...
http://systembytodd.com