Not an actual ad, but I think close enough to fit the thread.
After Dann Gallucci quit Modest Mouse, the band considered putting out an ad for another Johnny Marr -type guitarist to play on their next album.
Before they did that however, they had this crazy idea, and called up Johnny Marr (legendary Smiths guitarist for those are not in the know), who not only helped them make the record (We Were Dead Before the Ship Even Sank), but ended up joining the band for three years.
As the bands frontman Isaac Brock put it, "I just figured that just because he'd filled a massive part of his life building the Smiths legacy didn't mean he was busy at that precise minute."
