I feel like quite a few people in this thread don't know what "average" is. The average Canadian woman weighs 155 lb, stands 5'4", has a 34" waist, 41" hips and (natural) C-cup breasts (can't find statistics on band size), short-to-medium-length brown hair, brown eyes, white skin, and suffers from gingivitis. It's hard to quantify something like an average facial appearance however, plus the "average" face - a composite of facial features from all women of a given country or race - is actually going to be highly attractive to the majority of people in that country or race and not actually be common. But I think one can get my point.
Tugela and BadgerJohn also made some good points above about what different age groups consider attractive and why, and that we may be comparing people to false ideals (Photoshopped photos of models and celebrities with professional make-up and hairstyling etc, who we have never actually seen in person - even compare candid photos of Megan Fox to her magazine photos and movie appearances).
But I do understand what the OP is getting at. It is frequently a surprise to people, in particular, young people (both male/female) who have limited experience with the sex trade, to find that many SPs, including high-priced and successful SPs, don't look like Maxim models or whatever their own personal idea of the hottest-looking women look like.
The main reason is this: an SP's success is not primarily determined by her looks.
This comes as a shock to many people. But this is why reviews go into much more than what the SP looks like - a huge number of clients actually care a lot about things like about personality, charisma, friendliness/kindness, enthusiasm, reliability, services, open-mindedness, etc. I have known some very good-looking (by societal/media standards) young SPs who were not successful and vice versa. And obviously, as others have pointed out, we all have different ideas of beauty and looks aren't the only determinator of what makes someone sexy. However, I would still argue that on average SPs are more physically attractive to the general male population than the national average woman is, because looks are not irrelevant in this industry.
