From high-rollers who make $100,000 bets or from average people who play the dollar slots?
I don’t have the breakdown on “whales” vs. “fish”, but here are some numbers for 2010 on the breakdown: Examiner is back - Examiner.com
Table games were 45%, slots 50%, poker 2%, and sports books 2%. Gaming in general was 38.7% of revenue.
I’d tentatively guess that since 50% of the revenue was slots, and high-limits slots don’t seem that popular, that the majority of the revenue is from small- to mid-stakes players.
50% of the revenue isn’t 50% of the profits.
I assume slots are more profitable on a percentage of revenue basis because you don’t have to pay a dealer or lots of security personnel (to keep an eye out for counters and chip slippers and so forth).
However, that’s a guess; the cost of keeping quarter slots players full of free liquor and toting around all those rolls of change might even things out.
I was assuming that the margins on each type of game were roughly the same, since the casino can basically control the payouts of the slots. I see no reason to think that slots would have lower margins than table games or sports books. And poker of course has no volatility at all - the casino gets its cut no matter what happens in the game.
Still haven’t been able to find a break-down of revenue (or profit) based on bet size or anything like that.
Slot payouts are fixed by local law, I think.
The slots have the same approximate margins as the table games in Las Vegas specifically.
This isn’t really what the OP asks in terms of amount per bet being factored in, but this cite (PDF file) has a lot of data on the exact breakdowns of gross and net revenues based on game type in different states.
Las Vegas and Atlantic City, for example, have almost equal slot revenues but Las Vegas has more than double the table game revenue of Atlantic City.
I dunno about Vegas, but nobody uses coins in the slots at the places I’ve played. The machines accept bills, and pay out in a voucher that the player then cashes at a redemption machine, or at the cashier’s cage if the machine is down.
Beats me. I’ve never been to a proper casino. 
In Las Vegas?
[sub]Admittedly, I don’t understand precisely how the gaming industry works, so I would not be surprised if they made most of their money elsewhere.[/sub]
The Venetian/Palazzo makes most of their money from conventions, rooms and shops. That’s why they slashed the comps they give to players.
ETA: Qad - Wynn actually makes more of a profit in Macau than they do in the US.
Last time I was in Vegas (admittedly, over two decades ago), they still had the machines that produces the cacophonous clattering cascade of coins. At any given time in a large hall, some machine or another is going off, and the sound is good advertising (it makes the players thing “Oh, someone’s always winning! I’m sure to win!”).
I agree. The evidence for that is that these are the player’s that the Vegas casinos target. If there was more money to be made from “high rollers,” they wouldn’t let riff-raff like you and me in the door.
They still have the sound effects…just no actual mounds of coins spilling into a tray. The sounds are more electronic now…tones indicating credits being awarded…at least in Tunica and the Gulf Coast.
The games still make the noise because it’s fun to hear the jingle, but there are definitely no coins involved any more, and in fact the overall noise has been significantly toned down from what I remember. I hadn’t been to Vegas in over a decade either and I remember that same cacophony you mention, but when I went a couple weeks ago, while it was noisy, it certainly wasn’t overbearing.
I believe the sounds don’t always even come from machines in play. Some sound is just piped in. I was in a casino at 2 in the AM once that was pretty deserted and it was just as loud as when it had been full earlier in the evning.
When enterning Nevada on I-80 or I-10 westbound, there are tons of casinos on the state line. What is their purpose? Is it for die-hard gamblers who cannot wait to get to Vegas? “We’re over the Nevada border, let’s win some money now!”
I’ve excluded east-bound, since they’re close to Reno and Vegas. Perhaps with Primm, tourists can save a few bucks in the hotels there and drive into Vegas.
I have a friend who works in the money pit at a local indian casino, and he tells me most of the money they take in comes from the slots. It’s about 2 to 1.
The Utah/Nevada border town on I-80 is called Wendover, and it’s only around 90 minutes from downtown Salt Lake City, while Vegas is about a 6 hour drive.
Wendover has been separating hard-working Salt Lakers from their paychecks for many, many years…
Not really. With any care you can get cheaper rooms in Vegas. Primm exists to grab the “I can’t wait another 45 minutes to get to Vegas” crowd. Now it has an outlet mall as well, which brings in people who can’t be bothered to drive to Barstow.
The 10 enters Nevada exactly where? 