Since there have been music shows, there have been posters to help promote the upcoming show. The artist, record label, street team, or management would need to print out and distribute many posters to build public awareness for the artists. Although, we now have advertisements for bands online, promotional posters are still necessary.
Why? Because of tradition? Because it looks good? Maybe.
It is necessary for local bands that are not established to promote themselves with posters in the hopes that the right person would notice it and attend the show. That is not to say that these posters are only useful when there are local venues that the artist will be performing in though. The artwork or descriptions may be intriguing enough so that they would search for the artist online on facebook, youtube, twitter or whatever social networking site they are on. There are also many people,like me, that just enjoy the physical aspect of a poster. It is like how many individuals still purchase cds even though all of their music is on an ipod or mp3 player.
It is still relevant and people still purchase tour posters whether or not its because they enjoy the art, they want to keep it as a souvenir that they attended the show, they are a collector or they just want to help out the artist.
Check out this article as well for more reasons why promo posters are still relevant even in this digital age.
http://dailytekk.com/2012/07/30/why-print-posters-are-still-relevant-and-awesome-in-the-digital-age/
Art and Vibrations 
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