A lead magnet (a.k.a. an optin bribe) is something amazing that you give away for free in exchange for an email address. This doesn’t have to cost you anything to create– most lead magnets are digital materials like PDFs, MP3 audio files, or videos that you can create yourself at minimal or no cost. It can be absolutely anything you want, so long as it provides value for free.
The publisher ad server then communicates with a supply-side platform server. The publisher is offering ad space for sale, so they are considered the supplier. The supply side platform also receives the user's identifying information, which it sends to a data management platform. At the data management platform, the user's identifying information is used to look up demographic information, previous purchases, and other information of interest to advertisers.
Particular groups of customers can be targeted or even individuals. Offering individual customers special deals on merchandise and/or services on the customer's birthday, for instance, is one example of email marketing personalization. (A restaurant might send an email to customers on their birthday offering 50% off an entree,) Email marketing helps a business develop and maintain a relationship with a customer over time that hopefully results in increased sales and increased customer loyalty.