Despite the persistence of paint on the walls of the caves at Altamira and Lascaux—which are over 20,000 years old—and the writing on the walls of Pompeii, graffiti is a largely ephemeral affair.
The easiest surfaces to mark (sandstone, for example) are the naturally the quickest to decay. Spraypaint fades due to sunlight, automobile exhaust, and the elements. Wheatpasted posters and stickers decay over time.
Some works, however, (and like the earlier, persistent examples) persist over time, due to conditions of its display (on the street or in an art gallery), the materials from which it was constructed (newsprint or archival paper; spraypaint or etching compound), and the attention paid to it by passersby.
Shepard Fairey’s Hope poster (made for Barack Obama’s 2008 Presidential campaign) hangs in the Smithsonian institution. The Museum of Modern Art owns six works by SWOON. Residents of Bristol build protective enclosures for works by Banksy.
Simultaneously, a largely decayed Hope poster clings to a building in Chelsea; sixty wheat-pasted SWOON pieces disintegrated on the streets this week, year, month, whatever; and the city of Bristol buffed a Banksy mural just last month.
Similar sorts of claims can be made about virtually all forms of advertising that enter the public sphere: as advertising campaigns change focus, new advertisements replace the old; some people tend to write on, rip, remove, or otherwise alter poster and billboard advertisements; environmental factors also play a role.
This is one of the problems that I’m having with graffiti, and in fact points to further problems with a definition of graffiti.
In the past, I used the term ‘Street Art’ to denote graffiti that had a strong potential to become persistent or serve as advertising, including works by Shepard Fairey, SWOON, and Banksy, among others. This strategy worked well for a time, but became increasingly difficult to maintain: the concept of ‘Street Art’ is not robust enough to serve a useful purpose, especially since groups like the TATS Cru employ graffiti techniques in service of advertising campaigns for multinational corporations, and can be aligned with advertising, graffiti, and street art virtually at will.
Perhaps the concept of Street Art can be recuperated, but I am not yet at a stage where I feel comfortable reinstating the term or making any claims about its content. Ephemerality might be a decent starting point for this endeavor, but I have no confidence in this tactic either, since there are highly persistent graffiti works and completely decayed examples of objects formerly referred to as ‘street art.’
The main issue here is at what point an object becomes advertising, or at what point a work stops being advertising and starts being graffiti (or vice versa). I would be tempted to claim that legality served as the dividing line except that in 2006 TATS Cru put up illegal wheat-pasted posters throughout New York City as part of a “guerilla marketing” campaign paid for by SONY, not to mention Banksy’s community accepted and protected works, or Shepard Fairey’s HOPE poster.
Can graffiti be subsumed into the advertising milieu? Is advertising merely another form of graffiti? If we wish to frame the question in this way, I vote for the latter. But I’m highly doubtful that this would lead to any meaningful resolution.
I’ll leave this hanging for today. Perhaps further exploration in other areas will allow some progress to be made here.
 I also had (and have) strong personal misgivings about Capitalism and mistakenly employed ‘Street Art’ to stand for the “Bourgeois” expression of graffiti, versus the resistant, “Proletarian” forms like Tagging and Piecing. This serves no useful purpose, since graffiti in the Twenty-First century has become a part of the capitalist economy and really has no compelling reason to distance itself from issues of capital.