Participation Rate
Participation rate measures the share of visitors (or people exposed to the campaign, say through an email blast) who actually completed the giveaway's entry form. Example: if a landing page gets 10,000 visits and 1,200 people submit a valid entry, the participation rate is 12%. Not to be confused with conversion rate in the broader sense (which can refer to other actions, like a purchase after the giveaway) or with completion rate, which measures the share of entrants who finished an entire multi-step flow, such as a 5-question quiz.