 At his gallery, "Seth Siegelaub Contemporary Art", operating between the Fall 1964 and April 1966, for one exhibition Siegelaub encouraged visitors to lounge on couches and chairs to appreciate the show as an overall environment and hosted a four-day happening featuring the artist Arni Hendin.He was an aggressive promoter and paid as much attention to press and publicity as to the content of exhibitions, showing that even unconventional art work could be sold.After the close of the gallery he gradually became, in Joseph Kosuth's words, a "curator-at-large".