Many email newsletter software vendors offer transactional email support, which gives companies the ability to include promotional messages within the body of transactional emails. There are also software vendors that offer specialized transactional email marketing services, which include providing targeted and personalized transactional email messages and running specific marketing campaigns (such as customer referral programs).
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.