There are lots of ways to buy an email list, but none of them will actually benefit your campaign. Why? Since the owners of these email addresses didn't explicitly agree to receive content from you, there's no telling how interested they are -- or if they're even a fit for what you have to offer. A bought email list is also in violation of GDPR (we'll talk more about this in just a minute).
Another way to extend the clicks on your email beyond its shelf life is to prompt your audience to forward the offer. The folks at Litmus found that the most forwarded emails were 13X more likely than the typical email to include “Share With Your Network” calls-to-action. By including forward-to-a-friend (or social sharing links, as we discussed above), you put it in recipients' minds to share.