Like many digital ad campaign set-ups, Twitter charges based on a number of different actions taken by the user. When setting up your campaign you can pick and choose which actions you’d like to bid on and for how much. And you’ll only be charged when those actions are taken. Twitter splits these actions into 3 buckets: Awareness, Consideration, and Conversion.
Billable actions include the following:
Reach - paying for ad impressions on Tweets. This is an Awareness action.
Video views - bidding on cost per view (CPV). This is a Consideration action.
Pre-roll views - insert an ad before premium content (CPV). This is a Consideration action.
App install - pay when someone clicks a link to install your app. This is a Consideration action.
Website clicks - pay when someone visits your website. This is a Consideration action.
Engagements - increase engagement on your Tweets and pay per engagement. This is a Consideration action.
Followers - paying for followers.