That's a great point, like yourself I post silly stuff and mostly repost what I find on my favorite sites. However, on here I take time to write and think about what I'm going to write. Sometimes I spend all day thinking/drafting, all to ensure it's not nonsense. Being a new user,I know that it's gonna take time, which makes more sense to target bloggers on other non-paying social media sites then just typical Facebook users.
However, even though everyone says it and repeats it. The sting of having a post you spent some time on not get any attention hurts. Other bloggers would understand that and be more willing to stick to it for the long haul.