Wondering - How few pro punters keep the sport alive?

I have been a big supporter of owners and breeders as without horses there is no show
BUT nobody can deny that it is gambling that makes it an industry and not a hobby sport

When I see jackpots in the First Four result in the pool in the next race quadruple, I sometimes think that it is probably just a handful of big punters that keep the sport alive.

Lets take yesterday's Melton meeting
R.1 First4 had a pool of <$6k but when $4k jackpotted
R,2 First4 had a pool of about $28k
take away the 4k jackpot and lets say roughly 6k that would have been invested anyway and we have an extra $18k ie 300% came out of the woodwork in the space of about 30min
I doubt that there are that many on track and I suspect that very few 'casual' off track punters are even aware of the jackpot
I expect that at least $12k of that extra money came from a few big punters
Furthermore I would not be surprised if these same few are responsible for the majority of all the pools: win, place, .... with or without jackpots

It makes me think our sustainability may be fairly precarious and an explanation for why HRV pander to France to expand our pools

How few in number do you think these pro's might be OR do you completely disagree?

ps the figures are not one offs - the exact same thing happened in Race 4 after another jackpot and is pretty typical of how things usually go

The long shots got up in the 7th at Melton tonight and there would seem to have been less than a quarter of a unit on the First 4 (if my maths is good) so $3541 of the $5382 pool jackpotted.

https://www.tab.com.au/racing/2016-05-27/MELTON/MLT/H/7

Race 8 comes next and we see a pool of $20k for the First 4. On top of the jackpot, I make that to be $11k more than it would have attracted.

https://www.tab.com.au/racing/2016-05-27/MELTON/MLT/H/8

Everybody / pros love a crack at 'bonus' money
(I do always have a crack at Powerball after it jackpots a couple of times)