Ever since researchers realized that people could be invited to participate in research via email (wow, has it really been 20 years?), crafting effective subject lines has been an essential and tricky part of the research business.
What is the right way to invite someone to participate in research?
What words will have the least impact on the research results?
What words will result in higher agreement and completion rates?
Clarity: Obviously, the right way to invite someone is to be being clear, precise, and polite. Some people get hundreds of emails every day and they need to be able to quickly discern what you’re asking of them before deciding to even look at the email itself. A vague subject line will simply cause people to skip over the email completely. The subject line needs to clearly indicate that their participation in research, whether that’s a survey, focus group, interview or something else, is being requested. Tweet this!
Don’t interfere with the research goals: The subject line needs to be phrased very carefully so that it doesn’t impact the research results. For instance, let’s say the research is about motorcycles (or pain relievers or hair conditioner or teriyaki sauce). If the subject line mentions that product, a couple of scenarios are possible.
- People who dislike the product will be much more likely to NOT participate in the research. Consequently, incidence rates will be erroneously high and cost/profit predictions will be incorrect. Further, the research will be less able to determine why people don’t use and don’t like the product. It will be more difficult to understand product improvements that are necessary to increase use and purchase among non-users.
- People who like the product will be much more likely to participate in the research. As a result, incidence rates will be erroneously high and product usage estimates will be incorrect. And, purchase rates, recommendation rates, and likeability scores will be overestimated.
With all of these problems interacting with each other, it becomes impossible to know precisely how the results have been impacted.
If you know FOR CERTAIN that you only need to talk to product users, and that you don’t need to learn why people don’t like or don’t use your product, then you might be able to get away with mentioning the product category. If you aren’t completely sure, the best thing you can do is to avoid mentioning the product category altogether. Tweet this!
Choose persuasive words: Researchers have spent a lot of time trying to figure out which words are more likely to cause someone to take action. The Persuasion Revolution website lists 380 persuasive words and Buffer has also identified hundreds of persuasive words from a number of different sources.
In the context of an email invitation to participate in research, here are some words from those lists that might prove effective:
anonymous, be one of the few, be the first, because, before anyone else, discover, create, discover, easy, exclusive, free, guaranteed, help, hurry, increase, know, members only, new, now, privacy, protected, research, secure, tell us, today, today only, trust, understand, you, your
Don’t be afraid to be funny: If your questionnaire has personality, it could make sense to let that personality shine in your subject line. Try some casual words or some very common slang. But absolutely avoid outright humour, particularly political or religious humour.
What is the most effective email subject line? There is no single best subject line that will work every time. First of all, people get bored of seeing the same message every time and they learn that they can skip certain ones. Second, it’s impossible to control what other subject lines will appear right before or after yours, and that matters a lot! Choose clear, simple, generic, and persuasive. For example:
Tell us your opinions in this short anonymous survey
Help create new products by sharing your opinions in this survey
Only our members are being asked to participate in this research