That leaves out the dominant form of advertising: payola. Major labels spend a lot of the band's money to get songs on the radio, whether it's laundered through "independent promoters" or just cutting checks to Clear Channel. Then there's TV/Movies: the major labels are all affiliated with TV/movie studios, so the songs played on every teen-centric show are pretty strategically chosen.
FTFY. Label contracts pass the cost of basically everything on to the artist, so other than providing an advance and access to some slimy contacts, the label isn't really doing much for the artist (and in the end, the label owns the copyright on what the artist paid for... it's like a reverse work for hire).