I'm part of the e-book drop scheme for Coalition Troops. It is organised by Ed Patterson. He collates the email addresses of troops in Afghanistan and Iraq who have requested to join the scheme. Participating authors then send invitations by email to the troops for a free download of e-books versions written by those authors. The troops normally visit www.smashwords.com to use a voucher code to download the books free of charge.
I've discovered recently that hotmail is rejecting a lot of emails either wholly or to the junk queue of individual email accounts. I've been wondering why the level of response to the programme has been quite low, but checking through the list of addresses it turns out a lot of them are using hotmail.com. The microsoft email system may be free but it's crude email filtering means that opportunities like the E-book drop scheme are being lost to the account holders. Sometimes free is not cheap!