Buy 3 'Passion' books from eHarlequin and get your 4th free! There is a massive 148 book collection to choose from: and the prices start around $3.99 per book!
Most books are already 20% off, so a great deal together. Get free shipping when you spend $15, which is such a low threshold! I suggest keeping the currency in American if you can as you will pay a better price.
I have checked, and this promotion is not stackable: or at least not for me. Meaning if you buy 3 books you will get 1 free, but if you buy 6 books you won't get 2 free.
My suggestion is buy just enough books to get 1 free and hit the $15 free shipping threshold. :-)
Not applicable on eBooks. Sale ends 31st, May 2011.