Often artists will include product placements in their music video, which is a form of advertisement where branded products are used in context in the music video.
An example, and recent news headline, is Britney Spears' music video for 'Hold It Against Me'.
Since her last album being released in 2008, and last music video in 2009 for the song '3', it has been a while since Britney had been in the spotlight.
Her most recent video, directed by Jonas Akerlund (same director as iconic 'Smack My Bitch Up').
Coincidentally, it is the same director who made the music video for Lady Gaga, 'Telephone'. The 9 minute long video, which includes various product placements.
Virgin Mobile - A phone is snatched from a butch prison yard toughie's waistband (2:07)
Diet Coke - Cans are used as rollers in Lady Gaga's hair (2:22)
Wonder Bread & Miracle Whip - Those are the magic ingredients in sandwiches made by Gaga (6:35)
Polaroid - A camera is used to photograph Beyonce (5:45) [By the way, Gaga is Polaroid's creative director and inventor of specialty products after inking a deal with the brand in January.]
Also look out for Heartbeats Headphones (1:34), Chanel (2:17), PlentyOfFish.com (4:27), and Hewlett Packard (4:24).