Complex sentence: Their first album, "St. Elsewhere", was released in 2006; along with its first single, "Crazy", it was a major commercial success, and both album and single have been noted for their large sales by download.
Split into simpler sentences: Their first album "St. Elsewhere" was released in 2006; along with its first single "Crazy". Both single and album were a major commercial success and have been noted for their large sales by download.