The idea behind personalized subject lines, way back when e-mail software become sophisticated enough to merge the name data field into the subject line, was that people would be more likely to notice an e-mail with their name in the subject, which should lead to higher open rates.

Then, as always, the spammers latched onto that tactic and polluted its use for mainstream marketers. Spammers used personalization to attempt to trick readers into opening messages, making them wary of any message with a name in the subject. Delivery experts debate whether the personalized subject line has any utility anymore, and research into it -- will people open e-mails more readily or click the "report spam" button on them? -- isn't conclusive.

Personalized subject lines do have a place in the e-mail world, but only if they have a logical use. Personalization when poorly done ("Another Great Deal for $'YourNameHere'$") looks spammy and unprofessional.

Get the full story at ClickZ