Spacing on Pages is Off

hey everyone! for some reason ... the spacing is way, way off in a page that i just created on my blog. i can't figure out what the issue is. can anyone tell?

the page is at: http://xoxonettap.com/advertising-styling/

there are supposed to be paragraph breaks between the different sections (banner advertisements, text link ads, etc.), but they're not appearing for some reason.

thanks for your help!