Well, for several reasons.
#1, the customer is a small non-profit group that needed them in a hurry and had a tiny tiny budget...2 things that mix like oil and water. So, I knew the only way for them to get the price they wanted at the speed they wanted was to deal directly with the screen printer.
#2, the screen printer to which I referred them is a customer of mine. We are "strategic allies" with one another so it was not a big deal. I may have lost that transaction but have still retained the original customer and kept my alliance in tact.