Though we lack comprehensive data on the nature and scope of worker cooperatives in the U.S., researchers and practitioners conservatively estimate that there are over 350 democratic workplaces in the United States, employing over 5,000 people and generating over $500 million in annual revenues.Given the size of the US economy, 5000 people is not many.
However if you look at all cooperatives things look a bit different. The International Co-operative Alliance states that there are
30,000 co-operatives [which] provide more than 2 million jobsOf course cooperatives being big employers is nothing new for New Zealand given the size of Fonterra (17,300 employees as at 2012). But to put this into perspective Wal-Mart alone employs around 2.2 million people world-wide.