Another reason is it takes months of negotiations and 5 figure $$ sums per month to get leased lines in to the various exchange networks across the globe. Every

Another reason is it takes months of negotiations and 5 figure $$ sums per month to get leased lines in to the various exchange networks across the globe. Every exchange also has its own protocol, or variation of a common protocol, connectivity quirks, market model, data quality and normalisation issues etc. etc. Maintaining all this is expensive. Market data is an expensive game to get in to.