First a rhetorical question: what is art?
As with all things, that is relative. Beauty is, as they say, in the eye of the beholder. But where everybody have their own opinion on beauty, what is art is very often as dependant on the context as the substance.
Take, for example, a world-class violinist and place him in the subway, and very few will recognize him for what he is. Put him on a stage in front of an orchestra and people will pay several hundred dollars to see him perform.
And in an example from the other end of the scale, take a virtually talentless videographer and give him the tools needed to make derivative pop art, boosted by the words of already known street artists, and you have people flocking to his exhibition.
What to make of all of this? Simply put, people can not recognize art by themselves; bombarded with impulses, people need a large message, something to grab their attention saying "hey, look at this, this is really nice". Art needs a frame. Present a person with 100 of the best photographies on postcard-sized prints the reaction will be muted, but show him a really large print and the reaction will grow proportionate to the print size. This is what he is used to seeing as art, this is what he imagines it is like to walk around in a museum looking at all those large, splendid works of art. To him, it is equal to art, because it is presented to him in a form he recognizes as art.
If you want to be a big artist, make big art.