The Viewer In Art

I came across a website, fkartproject in which the artist is leaving small painted canvases behind in places and seeing who finds them where and takes the step of letting him know they found the canvas. It's charming. People who find the canvases get a kick out of their found treasure, and the artist gets his a kick out of his work connecting with someone.

It's not a new idea; others, for example, have done a similar thing with postcards. And a good deal of contemorary art invokes viewer interaction as a concept behind the work. In some measure, it's historical footnote to say art = Art because the artist says so. I find myself that I can't separate viewers from the work: connecting with viewers, to me, is essential for art to resonate. But the connection that happens is different from contriving connection. It's in vogue, but does viewer participation make art = Art or has it become another easy tagline?