A lot. We can get a small snapshot of the size of the market by looking at the production of large chocolate makers. There are only a few of these in the world, as opposed to the hundreds of thousands of confection makers, which buy bulk chocolate from these manfacturers. The largest chocolate maker in Europe is Barry Callebaut. According to their latest facts and figures report, they processed 435,825 metric tons of cacao in fiscal 2005/6, resulting in the production of 838,940 metric tons of chocolate and coatings.
If we estimate that this ratio of cacao to chocolate is roughly the same across the industry, we can use estimates of world cacao production to estimate the total world production. It looks like the world produces approximately 3 million tons of cacao a year, which would yield a little under 6 million tons of bulk chocolate going into the food supply a year. Fairly impressive that Callebaut manages to use about 14% of the world’s cacao supply.