I'm going to answer for my husband (we met on www.match.com).
His profile indicated that he wanted a women up to four years older than he. He was 37 at the time, he was interested in women as young as 30 and as old as 41. He advised me that he chose the age 41 as he wanted to have children and, realistically, women who are older than this might have difficulty having a child, have had their children already or not be interested in having children. If he was not interested in having his own children, he advised that he would have considered a woman as old as 50 for a potential partner. He felt that a woman 13 years his senior is still in his peer group and would not be old enough to be his own mother (well, I guess she "could" have been old enough to be his mother - but not likely).
BTW - he chose the younger range as young as thirty as he wanted someone who was in his peer group. Someone who had some life experience and was developmentally the same age as he.
When we met, I was 31 and he was 37.