Fantasy or Sci-fi series box sets. Any price, wide or KU. PNR and manchest covers are fine as long as it's not erotica. If the cover is too risqué this might not be the best promo either. Sharing once in your list is enough. If your mailing list is tiny, share on social media. Authors who don't share won't participate in future promos and might be excluded, unless you write and explain. Any list size is welcome, the information is just so that I know your list size.