Online Persuasion: When Can Offering Too Much Information Hurt You?

Which of these students – Tim or Bob – do you think gets better grades?

• Tim, who studies 35 hours per week.
• Bob, who studies 35 hours per week. He has one brother and two sisters and visits his grandparents every couple of months. He recently went on a blind date and likes to shoot pool on occasion.

If you’re like the subjects in an experiment by Henry Zuckier*, you’ll judge Tim to be the brighter student. Why?

The prevailing theory is that stating weak or irrelevant messages after a strong one may dilute the impact of the primary message. So in the above example, all we know about Tim is that he studies 35 hours per week – which is a lot. He must do well.

Bob also studies 35 hours per week. But somehow, all that additional (and irrelevant) information weakens the impact of the primary message.

What are the ramifications with respect to online communications?

We sometimes assume that our potential customers want to know everything. That by telling them a great deal about us and our products, they’ll feel more comfortable doing busines with us. (We may even appear more human and likeable, and isn’t that a good thing?) But beware… if that extra information is mundane, you’re going to appear more mundane. And who wants mundane?

Focus squarely on your strongest benefits, on where you stand out from the ordinary. Avoid anything that isn’t relevant, or that might appear mundane. It makes you appear more typical, more like “all the others”, which isn’t what you’re going for.

An Interesting Aside

Note that the principle also applies in reverse, to negative messages. For example, a politician who’s gotten very bad press can reduce its impact by broadcasting irrelevant information (e.g. family life, hobbies).

Take Sarah Palin for example. During her vice presidential bid, even many Republicans formed a negative impression of her due to some disastrous interviews and other blunders. But since then, she has appeared on TV with her family, enjoying the outdoors. And she’s seen much more positively now – even though all this extra information is not relevant to her abilities as a policy maker.

In both the positive and negative examples, the additional weak information makes the subject appear more towards the average. Good qualities no longer stand out; poor qualities are attenuated.

* Zukier, H. (1982). The dilution effect: The role of correlation and the dispersion of predictor variables in the use of nondiagnostic information. Journal of Personality and Social Psychology, 43, 1163-1174.