Today’s digital marketer has a lot of decisions to make. Which media channel is best for customer acquisition? Should its brand be active on Snapchat? What about Vine? And what happens if your closest competitor suddenly starts finding success with direct response campaigns on Facebook?

Another question marketers should ask themselves is whether to utilise cost-per-lead (CPL) or cost-per-impression (CPM) email campaigns.

The question is complicated due to a variety of factors. First and foremost, advertisers need to ask themselves what is their goal for email acquisition marketing. Is it to acquire as many customers as possible? Or is it to acquire as many quality customers as can be found for a given budget? How you answer these two questions largely determines whether you should pursue a CPM email campaign or a CPL email customer acquisition campaign.

Below we examine the pros and cons of CPL and CPM email campaigns, and also offer examples of what works and what does not when mailing CPL and CPM offers.

CPL Email Campaigns

Pros:

  • Buying on a CPL more often than not ensures an ROI-positive marketing campaign. There is less risk if you pay on a CPL basis because you are paying for each lead (and each potential customer) much further down the marketing funnel. 
  • The dating vertical works great with CPL email. Dating email campaigns perform best on the weekends when mailers are looking for high-performing deals. An insurance offer that is mailed on a Saturday on a CPL basis is not likely to attract a lot of sign-ups because most consumers do not want to think about buying a life insurance policy when they are relaxing on the weekend. But a dating CPL offer will often perform well on the weekend because many people are looking for this type of deal while in a more relaxed frame of mind. Often, mailers can meet and/or exceed their average weekday eCPM by mailing a dating offer on the weekend.

Cons:

  • You are not guaranteed a specific drop date. At any point your campaign can get trumped by a CPM email buy or even a CPC email buy, which is preferred my many mailers. 
  • Your lead flow, creative and landing page all have to be perfect. CPL email campaigns require smartly designed registration flows, great creative and performance-optimised landing pages in order to back out to the desired eCPM. Otherwise, you are just wasting your time and money, and that of your marketing partner, by trying to mail even a good offer using a bad landing page or email creative.

CPM Email Campaigns

Pros:

  • Guaranteed drop date for the email. CPM emails will typically be sent by your marketing partner in early or mid-week when email campaigns often perform the best. 
  • Time-sensitive verticals work very well with CPM. Verticals in which consumers often are deciding on a product or service to use based on a time-sensitive matter, such as health and beauty, insurance, finance and home services, perform particularly well with CPM email. Timing-wise, it is best to use a call centre that will call on the leads during set hours Monday through Friday, when consumers are most responsive. 
  • Reach specific demographics. If you want to reach a specific demographic or consumer target, then CPM performs better than CPL email campaigns. An example of this is health and beauty advertisers, which often need to reach consumers located in a specific geographic region and that have self-identified as having a specific ailment. Achieving this type of targeted mailing can often lead to more profitable leads. Even if your effective CPL is high, judge the CPM email campaign by its overall ROI.

Cons:

  • CPM email campaigns can be more expensive than CPL email campaigns. Often, you as the advertiser will be taking some upfront risk buying email on a CPM basis. Therefore, expect to pay more upfront for the leads (but, as noted, CPM email campaigns can back out to be more profitable than CPL email if they are highly targeted). It is best to shop around and get multiple references for CPM mailers. Ask them about their typical open rates, click-through stats and other pertinent metrics. Do the math and see if a small test makes sense to determine if a larger-scale campaign will be profitable.
  • Book early for holiday email drops, or be ready to pay. CPM email drops are all the rage during holiday periods as many advertisers seek to reach as many consumers as possible in order to make up for revenue deficits during the rest of the year. It is important to secure your CPM email drops early in the calendar year in order to lock in the best rates and inventory, especially around the holidays.