why is it that some co-operate organisation prefer to enlist the services of ladies as marketers than men?

Answer 1

Because like the old adage goes, "Sex sells."

Answer 2

Several reasons. #1 is that women generally have a softer voice, and therefore present a less confrontational voice. #2 is that sex sells. As the amount of women in higher positions in industry increase this will change, but for now the majority of decisions are still made by men, and some men are generally more willing to deal with a woman than a man. Like I said, Sex sells.

How many commercials have you seen on TV where there's a very attractive man or woman, and you cant even remember what the commercial was about, just how hot the person was?