Wondering how to entice your followers and leads to sign up for your mailing list? And how to make sure that only those who really want your email sign up, so that they help your deliverability and don't hurt it? The best way to do this is to offer people something of value for free if they sign up for your mailing list. This is known as a lead magnet, because it is attracting leads to your mailing list and to your business.