Alenty measures effective ad exposure for online branding campaigns using a generic Javascript that tracks visibility, exposure duration, and engagement. Traditional metrics like click-through rate are not suitable for branding as most clickers have undesirable profiles and there is no correlation between CTR and branding effects. Alenty's key metrics are visibility duration, exposure duration accounting for screen share, and engagement duration. These provide a more accurate understanding of campaign performance and recall lift than traditional served impression-based metrics.