Oh flash sale sites!
When will you learn that your congratulatory sign-up emails don't impress me?
If you must send an initiatory email, a succinct 'welcome' will do.
Even then, I will probably unsubscribe very soon, because I do not trust your 'send me less emails' option claim.
Does anyone else feel like your email is a never ending game to hammer down (unsubscribe) 'subscriptions' you once submitted your email address to? Like that arcade game where one hammers down those pop-up objects... that only pop up in another spot a second later.