A) most people who have a PSP and a PS3 use the PSN with both, especially since until recently you more or less had to have a PS3 to get any utility out of PSN with the PSP. The number of PSP only people who use PSN is almost certainly pretty small, certainly not more then the 3+ million that would put PSN users below live users.
B) Live without payment is more or less meaningless. What can you do with live Silver? Watch trailers, download games and have a friends list. That is really about it. Silver is meant as solely a way to funnel people into gold (with a 50% success rate). PSN on the other hand is fully functional so that whole 20 million can play games online and do everything a gold member can do except pay 49.99 a year. I would rather have the full population able to play multiplayer games with me then a population that is only half online game capable.
C) if you use game for windows live (which some new games like Fallout 3 encourage and other new games like dawn of War 2 more or less require) you are included in that total. So if you are going to accuse Sony of double dipping you certainly have to say the same about Windows Live. They DO roll them together, in fact if you get achievement on a windows game it now posts to Xbox live (check impulsivity, my live account, it has achievements for Dawn of War 2 which is PC exclusive).
D) are you really citing Microsoft making you pay to play games online (which neither the PC, nor the Wii and PS3 does)? I mean that revenue is almost all you and others like you being extorted for 5 bucks a month to play games MS by and large did not make online. I would rather buy a new game then pay every year to play Call of Duty on live with that 50 bucks thank you.
In terms of revenue thats not from a service fee for use of full features, I would doubt that Live is ahead (in terms of game/media sales and the like, which is where Sony is getting their PSN revenue). Overall there are more exceptional games on PSN as well (and the best games aren't just available on the PC like with most Xbox live games like Braid.)
PSN ID: ChosenOne feel free to add me
