I have Android 4.4.2. On a couple of apps (like Huffington Post and NBC 4 LA)I've noticed different banner ads that appear on the bottom of the screen inside different apps. The thing is these banner adds on the bottom of the page look very similar. I don't know if these apps use the same advertising company or what the situtation is. They're right on the bottom of the page so when you're scrolling you often hit them when I don't want to.
Are these normal or do i have a virus that installs adds inside some of my apps on my phone?
EDIT: I've added an image of the type of ad. This type of banner ad appears on the bottom of the screen inside different apps on my phone. Is this normal?