The difference is how often you pay your subscription fee. With monthly billing, you will be charged on the same day each month. With annual billing, you are charged once for the whole year.
Once our tag is added to your tag manager, invalid audience lists are automatically generated and fake traffic can be de-targeted across all your major buying channels like GoogleAds, Facebook, DV360, Linkedin, Twitter and many more. Further you can remove fake traffic using our analytics suite and see where fraudulent traffic is coming from by campaign, channel, geo, keyword, OS level data etc.