Share 'Blog Carnival - How will it effect your branding?'

Hi - I'm new here and I've made some friends already..thanks for adding me. I have a quick question relating to "Blog Carnivals" (which I only really found out about yesterday when I joined this community.) They look exciting on the surface. I have checked out a couple and they seem to really take over your blog....will this hurt your branding? Is it a good thing to host one of these babies...I…