Siren Bookstrand is a popular publisher of romance and erotica. They only publish books that end happily ever after. They publish many books every year and most authors seem happy with the work that the Siren Bookstrand editors do. They are primarily an electronic publisher, but they also have print editions.
They are most known for publishing books about menages, and they have more than one line devoted to menages. Authors who have published more than one book with them say that the menage books sell the best. So that is something to keep in mind, if you have a book that features one. They do also publish more mainstream, traditional romance novels, but as a publisher that is not what they are known for.
All of their imprints are looking for very specific things in terms of content so read all of the guidelines for the imprints very closely.
They also have very specific guidelines. Make sure to read all these guidelines closely before submitting.
They only consider work that is longer than 20,000 words in length.
To learn more, visit their website here. You can read their submission guidelines here.