A lot of mailchimp campaigns I receive start with… “Use this area to offer a short teaser of your email's content. Text here will show in the preview area of some email clients.” This happens because the creator has forgotten to update this text in the campaign, and means that the first thing your potential customer sees is an error, rather than a punchy selling statement or teaser to make them open the email . This screenshot shows how the email looks to the recipient (top right) and how to fix that problem in the MailChimp campaign view. It only takes a second to fix, and is definitely something you should add to your checklist for sending out MailChimp campaigns. Happy MailChimping. 

How to fix a very common error in Mailchimp Campaings - failing to update the teaser line