Some people believe email marketing is dead. While I personally don't feel that way, it could certainly use a shot of adrenaline. I started my Digital Marketing career in email marketing, so I'll try my best to do so. In my experience, the problem with email marketing, is bad email marketing. Emails that are wordy, untimely, or irrelevant can easily do more harm than good and leave recipients with a negative impression of your brand. Beyond that, many advertisers don't see the value of email addresses beyond traditional means. With Facebook, you can reach these customers and prospects outside of their inbox.
I'll start with Facebook. Custom Audiences built from your email list allow you to target these individuals on Facebook, and serve them relevant ads. Facebook does this by searching for profiles with the same email address, and making a match. You can expect about a 60% match rate since people may not be using the same email address on Facebook. This often occurs when your email list has a recipients work email address as opposed to their personal email address. For prospects, you can use this as a lead nurturing opportunity. When targeting customers, this is when things get really amazing, and it's time to start segmenting your list. You now have the ability to show this audience ads featuring similar products to what they've already purchased as well as compliments. Say for example, you sell someone a television, and acquire their email address during the purchase. Why not follow up a week later with a Facebook ad for a Blu-ray player that you sell as well?
Google recently launched a similar offering, Customer Match. Historically, Google targeting has been a bit of a challenge by design. This is because an advertiser is supplying the information a person demands, without being able to properly pre-qualify the person as an ideal customer. For example, someone searches for "2016 Corvette", an ad appears, and they click on it. Unfortunately, you may be serving your ad to a 14 year old kid who's really into cars, but hasn't saved up enough allowance to purchase it. However, you will get charged when he clicks on your ad. With Google Customer Match, you have more control over how your budget is spent for your most sought after customers, those who you have pre-qualified based on their past behavior.
In both cases, another huge selling point is the ability to create lookalike audiences based off your email list. This gives you the ability to target other individuals who have behaviors and interests that are similar to those on your email list. Utilizing this option is an excellent way to scale your budget, with high value audience.