Book marketing

I've now got my books on Smashwords as well which allows for a great deal more formats to be downloaded.  I've also decided to drop my prices greatly - on advice from elsewhere.  Sales are steady but low and I need to kick start interest.
Just starting on book four a sequel Jacaranda.  It will be set in two times streams again.  The past time will be 1792 when the French reign of terror came to the Caribbean.  There is a guillotine blade in the National Maritime Museum which was captured from Guadeloupe. The only problem is that the facts about it are all wrong, even the Museum admit that and are now looking at me to solve the puzzle.  It should make a fascinating backdrop to the plot..........