Don't forget the P.S. and the P.P.S. This is often forgotten by many and is one which is likely to enhance your conversion rate. At the tail-end of the copy, is always an effective location for the PostScript (P.S.) and the Post-PostScript (P.P.S.)-- in the form of a summary and where you can remind your reader to Opt-in or get your complimentary eBook. Make your end cordial and friendly, but never too aggressive in tone nor content.