As long as you truthfully state what it is you are doing and what will happen when the user leaves their email - their is nothing sleazy about this.
I've seen people recommend doing exactly what I described. Obviously, being honest about what's up is not a bad thing, but that's not what I was talking about.
As long as you truthfully state what it is you are doing and what will happen when the user leaves their email - their is nothing sleazy about this.