RE: To tweet or not to tweet?
When you tweet about something add a single word that relates to it with a # tag and no space between the # and the word. Then it shows up on all the threads associated with that word. For example: I have a novel that has a lot to do with WWII. I follow a fascinating tweeter called RealtimeWWII who tweets things that happened in real time on this day in WWII, they are up to 1940 now, so today was Jan 29th 1940. By adding a #word they reach lots of other lists. I retweet some of their stuff and blog about other tweets of theirs and add #tags that relate to my novel
If I tweet about a review or sales figures or a great article/link that relates to my book's subject matter I add #WWII #Holocaust #music etc. They all tags that relate to my subject matter and they reach people who don't follow me but do read the lists associated with those words. I put the Amazon link in and the sales figures shoot up.
#indie #author #selfpub will get you on good lists too.
You can use this for retweets, discussions etc. I follow some well known writers and I find they follow back and answer tweets. Joanne Harris is great, she and I tweet quite often and she had a look at the cover of my next ebook and made some suggestions about font etc. But we have been tweeting for awhile.
@TweetYourBooks is a good one to follow, if you tweet them with info and links and ask for a RT they will often do that and it reaches lots of people. @Books2Heart is another good one, you can list your book/cover/blurb there for free and they will happily tweet about it to all their followers for free.
Be witty, be interesting, find people interested in the subject of your book and retweet them with #tags and you will grow your audience. My next book is a murder mystery set in a vineyard, I followed some carefully selected wine tweeters around the world and almost all of them have followed me back so they will be on my list when the time comes to do a publicity tweet.
Hope some of this helps