The impact of a contest on email and social media leads is not easy to quantify. What I have found out through trial and error is that contests can be used to generate email subscribers and social media followers if the contest is created properly. I previously went over those steps here: How to Create and Run a Giveaway Contest on a Website and reviewed a web application that can be used in that running a contest here: Rafflecopter Review: Contest Widget for Giveaways, Sweepstakes, Raffles. The infographic below illustrates some of the benefits of using contests and giveaways for lead generation but it does not show ways to advertise giveaways, contests, sweepstakes for high entries.
Within the infographic, there is an Industry Breakdown (Content Websites applies to entertainment industry websites) and the best time to acquire email subscribers (which I do not agree with. People with a 9-5 job are asleep or going to asleep by 11 pm). The times enumerated here: How and When to Promote Contests, Giveaways, and Sweepstakes on Twitter to Maximize their Pageviews are more appropriate in my opinion.
The Impact of Contests on Email and Social Media Leads Infographic:
Impact of Contests on Email and Social Media Leads Infographic