Something takes up a large portion

Ok, thanks Grammar Geek, Marius.

It is more of the idea that it (visual media) has become (most) prevalent (and important) in our society. So I don't really want to use the word 'market' there.. maybe I can just use "visual media has become most prevalent in our society"? Thanks for the suggestion though Hoa Thai.

Mmm.. most prevalent 'thing'? The only other word that comes to mind is 'media', but I wouldn't want to limit it to media, but it's more of a general concept. I'm sure there's a better word for it, but I can't think of it. Looking up prevalent in a dictionary, I came across an example "Colds are prevalent in the winter", which makes me think "Visual media is prevalent in our society" would work, and without mentioning of the what. What would be the reason for this? Nevertheless, your sentence would work..

Edit: ah.. maybe it's the mention of 'most'?

Thanks.