Subject line of marketing email impacts overall click rate but this field is generally given a miss. Strong subject body is essential for effective mail marketing. So, do not stress more upon announcing the discounts in tag line, try to bring the viewer on the website.
Yes, Subject line plays a major role in a email. Improper or wrong usage of it is never appreciated, so best impression is gained for a mail only a proper subject line.
Whether you're distributing an email blast to your customers or sending an email to a targeted media contact, the effectiveness of your efforts can hinge on the words you use in the subject line.