The International Movie Data Base is a great source to find out what audience and critics think about films and what people are enjoying the most.
As you can see in the screenshot, 28 Days Later, a zombie movie, was rated number 1 on the top 80 horror films. This suggests that people from many ages and backgrounds may enjoy zombie films. However, they may have enjoyed this film, but may not enjoy all zombie films. this means that we needed to delve deeper and see what our target audience wanted to see and enjoyed.