Complex sentence: A July 2010 study conducted by NPD Group failed to list GamersGate among the top 5 digital distribution companies, however this study was disputed by both GamersGate and Impulse (who also failed to rank).
Split into simpler sentences: A July 2010 study conducted by NPD Group failed to list GamersGate among the top 5 digital distribution companies. However, this study was disputed by both GamersGate and Impulse (which also failed to rank).