Do open rates matter?

Ken Magill over at DirectMag has an article deriding the reliance on ‘open rates’ as a metric for the success (or failure!) of marketing campaigns.

E-mail delivers a return on investment so high, it’s practically embarrassing.
It doesn’t require getting fuzzy with the metrics.
But as long as we continue to call the percentage of graphics displayed in a given campaign its “open rate,” we’re being dishonest with everyone who doesn’t know what the metric truly means. And as the national “open rate” continues to drop, the lie gets even bigger.

I have to wholeheartedly agree with Ken here. “Opens” have always been something easy to measure, but hardly anyone actually understands what it means. Open does not mean that someone opened the email, open just means that an image in the email was loaded from the sender’s server. There are a lot of reasons an image might not get loaded even when the email is opened and read by the recipient. Some people, like me, choose not to load images by default. Some ISPs block images by default. Some companies block images. A very small fraction of people use mail clients that do not render images at all. All of these factors will affect open rates.
Measuring performance, real performance, of email marketing is important. Open rates are really not a measure of performance.