In addition to keeping an eye on comments and stalking all those lovely new potential readers, you'll need to monitor your social media during the tour days. Keep an eye out for anyone who retweets or favorites a tour related post and be sure to thank everyone who helps spread the word. Again, this is the beauty of a hash tag. If everyone is using it, it makes it easier for you to thank them.
If you include tweetable links in the post content it makes it even easier for you to track interactions and thank everyone who is helping you spread the word.
You can reply to folks publicly to thank them, but watch out to make sure your feed doesn't become one boring string of links and thank yous. It's okay to thank folks in a group tweet or even by DM if you are following each other. It wouldn't hurt to include some non-tour related tweets during the day to keep your stream fresh.