You have your recipient - he/she has read - and maybe ordered.  But then what?

The next time you email with the link you might get an immediate click through because you have excited them last time.   When play.com first emailed me with details of their CD sale I clicked through, found lots of CDs and bought them at cheap prices.  The next time they wrote I was straight there, because the previous experience was great.

But what if the last experience was not great?   Why should they try again?  And what of the people who found one thing, bought it, but don't really have a mind to come back to you?  What draws them in?.

You have to have a retention programme - something that makes them come back to your site even if they are not buying.   For most people this means news, but it can mean articles, exciting special offers, games, stories - anything.  But just like a real shop in the high street you have to make it a place which your customers perceive as worth visiting even if they doubt that they will buy anything.