1. Don't spam people on Twitter with "buy my book!" direct tweets, most particularly when you've never interacted with them in any way EXCEPT to send spamming tweets.
2. If you must spam people, know that they may well go to your tweetstream to see if you've spammed other people (you have) and while there may note that you also rated YOUR OWN BOOK on Goodreads, and gave it 5 stars.
At this point, you will be deemed a fuckwit*, and blocked.
*not only because you rated your own book, which is beyond tacky, but because you were idiot enough to let that fact get boosted to your twitterstream.
- under the heading of "don't do that"