For about 10 years, I ran $2 quads, once a month. The only prize was free entry to the next event if you finished clear first in your quad. I think that I calculated that I broke even on 2 quads. (having a FREE SITE certainly helped).
Attendance at these monthly quads varied somewhat, ranging from 8 to 40. This was comparable to local attendance at Swisses held 3-4 times/year.
Quads are VERY easy to administer and run (so the TD can play if there is an odd number of entrants). If you add “the first three rounds of a Hex” at the bottom, you can handle any number of players (the TD always makes it an even number). No pairing between rounds, so we could fit 3 rounds of G/45 in a Sunday afternoon. I used pre-printed templates, so all I needed was a pen (and a coin to flip for colors). All administrivia is done before the first move.
Oh…if the “first 3 rounds of a Hex” is the bottom section, you can often get all 5 rounds of the Hex played while everyone else is playing 3 rounds. Note that there is NO POINT in trying to run the Hex as a Swiss. None, zip, nada, zilch, bupkis.
One upside of quads is that most games are “competitive” - this can be a problem in a small Swiss with a wide range of playing strength. One downside is that players tend to see the same opponents month-to-month. So…do the players want good games against people they know, or walkovers with strangers? I would usually accomodate requests to move a player up or down one quad if that helped avoid a common opponent, or a family member, or… as long as it was a reasonable switch.
I had one Master who won the big prize: free entry for life, after winning the top Quad 3 months in a row.
As I recall, the only reason I stopped doing this was that my liaison with the University (who provided a FREE SITE) screwed up and failed to book the site. He insisted on running everything for 3 years - until he burned out without training a replacement. Perhaps it’s time to start up again.