No, sending out tweets of your book won’t result in anything that is considerably positive. In fact, it is a waste of time to spam your books on Twitter. If your primary goal is only conversion then stick with Facebook. THEN WHY USE TWITTER?
Are there only two choices? Can you risk working with a self-publisher that requires payment while trusting they will do a good job or publish with the traditional presses that offer declining revenue? You can self-publish; many established authors market their material so that they can guarantee full control. This can be very difficult, and it leads many authors to wonder how to pick a publisher that charges and provides good offers.