Or even invite your author friends and join our competition to win a free book cover. (bookcovers.io)
Please join us if you want to talk about SF / F and maybe win some free books. (bethcato.com)
In the beginning you need to keep reminding them why they joined and why you're emailing them, and I usually post something on the bottom like «I use this list to give free books away to fans of YA fantasy and scifi books; if you're no longer interested in winning free books please unsubscribe.» (creativindie.com)