American culture is heavily influenced by celebrities. We are a very celebrity-focused society so when you are able to use a celebrity that's known & respected...View More
amongst your audience, it's a no-brainer. Hillary uses this strength in her emails. It's not often that someone gets an email addressed to them by a celebrity. By using personal subject lines, it truly feels like you're receiving an email from them which makes it hard not to be curious & click. Hillary uses a variety of celebrities that target different voter segments & in two cases, offer the opportunity to party with them which likely got a ton of opt-ins.
