When it comes to your email list, are you looking for quantity, or quality? Many marketers would say “both!” But what does quality mean when you’re using opt-in advertising? And is it different with single opt-in vs. double opt-in? While we’re strong proponents for double opt-in, we recognize that it doesn’t always make sense for every business. Single opt-in offers a lower cost way to generate leads that are a little less qualified, but still a great addition to your database.