Complex sentence: Although ARCs are usually free promotional items, some early versions of books are sold to the public while labeled ARCs, "e.g." Captain Vorpatril's Alliance by Lois McMaster Bujold.
Split into simpler sentences: Although ARCs are usually free promotional items, some early versions of books, even some labeled by the publisher as ARCs, are sold to the public. An example is Captain Vorpatril's Alliance by Lois McMaster Bujold.