Aided by the text-analysis program Linguistic Inquiry and Word Count, Bruch and Newman discovered that men generally had lower chances of receiving a response after sending more "positively worded" messages. When a man tried to woo a woman more desirable than he was, he received a response 21% of the time; by contrast, when a woman attempted to court a man, she received a reply about half the time. In fact, over 80% of the first messages in the data set obtained for the purposes of the study were from men, and women were highly selective in choosing whom to respond to, a rate of less than 20%. Therefore, studying women's replies yielded much insight into their preferences. Bruch and Newman were also able to establish the existence of dating 'leagues'. Generally speaking, people were able to accurately estimate where they ranked on the dating hierarchy. Very few responded to the messages of people less desirable than they were. Nevertheless, although the probability of a response is low, it is well above zero, and if the other person does respond, it can a self-esteem booster, said Kaiser. Co-author of the study Mark Newman told BBC News, "There is a trade-off between how far up the ladder you want to reach and how low a reply rate you are willing to put up with." Bruch and Newman found that while people spent a lot of time crafting lengthy messages to those they considered to be a highly desirable partner, this hardly made a difference, judging by the response rate. Keeping messages concise is well-advised. Previous studies also suggest that about 70% of the dating profile should be about oneself and the rest about the desired partner.