When coming up with the plan to market your book, you have to have in mind who your audience is. You cannot have a successful campaign unless it is target to a specific group of people. But have you considered the other component that you may not have that greatly affects you reaching that specific audience? If you have not thought of how different time zones affect your promotional efforts, your book may not be reaching its full marketing potential.
Once you confirm who the market is for your book, you have to consider where they are most situated and if they are located in another time zone than you.
Other things you should look into if your audience is located elsewhere than you: which social networking website they most spend time on, when they do, and what time that is for you.
If your book promotional efforts are not going the way you expected or planned, perhaps it’s time for you to consider the timing of your activity and when the best time for you to “strike”.
Read details about how to look into how to find out if your audience is in different time zones at Jane Friedman’s blog.