exactly. i'm getting better fills, even when I use a market order The mathematical value is 3.43. Instead of being filled at 3.43, I get filled at 3.5. Maybe MM are tipped off to TOS orders and fill those ones in increments of 5 or 10 cents , giving some of the profits back to TOS and keeping the rest to themselves.
http://securities.stanford.edu/filings-documents/1052/TAHC00_01/2016323_r01x_14CV00396.pdf Plaintiff Klein alleges that TD Ameritrade's routing of orders to the venues offering the highest order flow payments amounts to a routing strategy that is inimical to best execution. Further, Klein alleges that TD Ameritrade has profited in the amount of one billion dollars as a result of improperly routing orders based on the distinction between a marketable and non-marketable order, stating that "n a June 12, 2014 press release, TD Ameritrade disclosed that from 2011 through 2013, it received at least $605 million in payments for order flow alone." From the TS ameritrade SEC filing Order Routing Matters — Five putative class action complaints have been filed regarding TD Ameritrade's routing of client orders. The cases are pending in the U.S. District Court for the District of Nebraska: Jay Zola et al. v. TD Ameritrade, Inc., et al. ; Tyler Verdieck v. TD Ameritrade, Inc. ; Bruce Lerner v. TD Ameritrade, Inc. ; Michael Sarbacker v. TD Ameritrade Holding Corporation, et al.; Gerald Klein v. TD Ameritrade Holding Corporation, et al. The complaints in Zola, Klein and Sarbacker allege that the defendants failed to provide clients with "best execution" and routed orders to the market venue that paid the most for its order flow. http://blog.themistrading.com/wp-co...meritrade-Inc.TD-Ameritrade-Clearing-Inc..pdf https://topclassactions.com/lawsuit...posed-illegal-kickbacks-class-action-lawsuit/
Payment for order flow is a legal practice. I did not read any proof that customers got harmed in the process. The high frequency firms get there faster but that does not mean that at the time TOS customer gets order to the counter-party that he is not getting the NBBO price. That said it was an interesting read.