Dear Laurence, I'm sorry to say that I didn't see any impact in my sales. Most disappointing was the email sent to 100000 subscribers (it might have brought 40 sales) + the hero spot on your mail. Maybe you can prove me wrong with the statistics of the Twitter clicks. My book - although having 151 reviews on Amazon.com with an average rating of 4.6 - might just not be right for your audience. I expected a lot more given that a 300 EUR investment with bookbub brings me sales of up to 4500 EUR the following 3 months. (The bad thing is that my new books are not accepted by bookbub.) My 200 EUR investment with BGS brought no ROI worth mentioning. Sorry. Best, Marc