Readers have very little to go on when they decide whether to open your email. Other than their own mood and personal time, they have:
- Sender name & email address
- Previous experience with your emails
- Subject line & maybe some preview text
So how does the length of your subject line affect open rates? Is a long subject line (such as the one on the Klick Wire -Ed.) better, or is a shorter one better? Marketing Charts has an answer:
Looking at this data it seems like shorter is better. If possible, get right to the point and your readers will thank you with (slightly) better open rates.
Source: Marketing Charts