Definition: A double opt-in is adds an additional step to the email subscription opt-in process, requiring a user to verify their email address and confirm interest. Double opt-ins signify a higher level of user interest, though its effectiveness has been both lauded and disputed by marketers.
Use of the double opt-in is a hotly contested subject among email marketers. Double opt-ins reduce mailing lists by adding another step to subscribing, filtering out passive prospects, bad emails, and spam accounts in the process. One study found that over 23 percent of initial subscribers failed to verify their email during the second opt in, a significant reduction in overall reach from single opt-in campaigns.
Though email marketing is built on acquiring as many prospects as possible, some marketers claim that this increased focus is more effective in the long term because it allocates resources to more qualified prospects and gets rid of bad emails. Conversely, not opting in the second time doesn't necessarily indicate outright disinterest.
Though varying studies purport greater success for either model, there is no clear winner. With various other factors impacting the results — email content, subject lines, brand, and the rest of the drip campaign — the only way to find out what works for your business is to try both. Try testing both methods and keep as many variables steady as possible.
Also consider your immediate goals: