every low cost data may share data imput with main venders(my view) or excute other technology. they may extract data from odin etc and backfill as lagging , they deliver probably from their server.
some also use yahoo or google data and send through their server for cash scrips.
now company like manshi deliver a software which can extract realtime data from ur broker terminal,like odin ,tradetiger.
i am using their software and there is near 0 delay as it extract from ur broker terminal(provided ur terminal is ok and net). their data is smooth and backfilling is also good.
also with the use of odin,tradetiger, ttadvance. u can use it for cash,future and comodity with one software liscence.
manshi.co.in