Think about it this way: When you get new information that according to your trading algo might move the price of a stock and you want to act on it, once you ha

Think about it this way: When you get new information that according to your trading algo might move the price of a stock and you want to act on it, once you have made the decision you want the time for your order to reach the exchange to be as low as possible as you assume others can have the same info and act to it accordingly. Not just anyone can have a direct market access connection to an exchange's order book. This is usually reserved to the members of the exchange, and many rules and regulations apply. So even large volume traders use Sponsored Access, transacting directly with the exchange through the access platform of a sponsoring member that ensures not just technical service but most often also some risk and regulatory compliance controls. This service is not provided for free. GS competes with a few others to provide such an access platform. Reducing the overhead latency of the platform itself in the trade loop makes them more attractive and allows them to attract HFT clients and/or maintain healthy margins.