5 Ways To Measure An Audience.

Online Surveys.
Pros = It is quick and easy, you dont have to do it if you dont want to and brings people onto the certain site to bring customers.
Cons = People wont do it if they dont have the internet, People wont do it if they dont want to, Some people might get confused with the idea of going online to do a survey.

Phone Surveys.
Pros = You dont have to do it if you dont want to, The data will be going straight to the people making the survey, Quick and easy.
Cons = People might not give the correct information, Time consuming for the surveyors, People might not do it if you call them.

People Meter.
Pros = You get the exact information like age and sex of the person, People have to do it if you put it in their house.
Cons = Might be expensive and its alot more space consuming then using the computer you already have.

Polls.
Pros = If its on internet it will attract people to the site and if its text it gets a good variety of people.
Cons = Relies on people to do it themselves, and might cost money for people to text through.

TV Competitions.
Pros = Shows what type of people watch that show at the time, attracts people to the show.
Cons = People might not be able to take it cause they might be at work etc.