Real-time price data is indeed not free, but widely available even in retail brokerages. I've never seen a 15 minute delay in any US based trade, and I think I can even access level 2 data a limited number of times on most exchanges (not that it does me much good as a retail investor).
> I would guess most of the profiteering is from consumers not knowing the last transaction prices?
No, not at all. And I wouldn't even necessarily call it profiteering. Ironically, as a retail investor you even benefit from hedge funds and HFTs being a counterpart to your trades: You get on average better (and worst case as good) execution from PFOF.
Institutional investors (which include pension funds, insurances etc.) are a different story.
> I would guess most of the profiteering is from consumers not knowing the last transaction prices?
No, not at all. And I wouldn't even necessarily call it profiteering. Ironically, as a retail investor you even benefit from hedge funds and HFTs being a counterpart to your trades: You get on average better (and worst case as good) execution from PFOF.
Institutional investors (which include pension funds, insurances etc.) are a different story.