Free trade allows cultures to get things from countries that they would not have access to otherwise. This allows for more understanding of other cultures. Certain countries would not have access to technology, certain foods, and a number of other things. Having technology allows for communication around the globe. This is good for culture.
Thanks to the benefit of a global economy we now have the ability to have an interactive and highly diverse global culture. No longer are regions of the world isolated due to a lack of understanding of other cultures. A unified global understanding of cultures allows for the expression of ideas without any sort of culutral barriers.