When it comes to our reports based on data from Diamond Comic Distributors, we're always careful to say they're based on sales to retailers by the distributor in North America. We often mention UK and European sales as not being included in Diamond's monthly tallies — but we don't often get into why that's the case. The question is occasionally raised online, so it's worth a quick primer.
Diamond launched its own service in the United Kingdom, Diamond UK Ltd., in 1991; later that year, it purchased another UK distributor, Pacific Distribution. In 1992, near the height of the comics boom and Diamond's rivalry with Capital City, the company bought out Titan Distributors. The consolidated firms operate now as Diamond Comic Distributors UK; headquartered in Cheshire, it serves both the United Kingdom and Europe.
How big a market are we talking about? For many years, I drew upon internal data for publishers who accounted for more than a third of the U.S. Direct Market — and I got to see their North American and UK invoiced orders side-by-side.