Bad behaviour in a dayseat / rush queue

Well are these tourists or locals? Locals don't have to go and see the sights!  They might just treat it as some fun sort of camping with like-minded people. I would never do three days in advance - the worst was about 6-7 hours in advance for Robbie Williams some years ago (don't judge me). It was summer, we could spend the time on a nice lawn with a picknick and had nothing better to do anyway.  Besides I have the sense that if I fork out a ton of money for a big concert, I'd like to see the artist in question properly, facial expressions and all, not just a tiny ant far away. 

This said, I'm now too old and lazy to bother with endless queuing, so I've mostly been giving big pop concerts a complete miss. 

Don't have a problem with it - one out one in, leaves me where I was to start with. Joiners though, are an absolute no-no. I remember queuing for a show at the Beeb (free audience tickets - non-priority). All six of us got there hours beforehand, were 2-7 in the queue and by the time we were down to 13-18. Words had been exchanged but short of physical violence, they were not going to shift. Thankfully our whole group got in, but we were the last people to do so and all 12 of the people behind us were there before the late joiners up front.

Place holding is much more common on broadway I believe. The idea of someone effectively buying their place at the front of the queue doesnt sit well with me though. As @emicardiff has said it takes that place away from those for whom cheap dayseats are their only way to afford the ticket

But in the case of, say, this Angels queue, if Bloke 2 arrived at what was obviously his preferred time without Bloke 1 placeholding, he'd have arrived after me and I'd be one place further along. So it wouldn't be a straight swap.

But Bloke 1 WAS place-holding so you weren't one place further along. Sorry, but I still don't have a problem with it, save in the "paying to place-hold" scenario discussed in other comments. I live a long way from London so getting to a day-seat queue very early is impossible unless I stay in town the night before which rather defeats the object of queuing for cheap tickets! If I had a friend generous enough to get up early and hold my place, I would be extremely grateful to them and really not feel that I was depriving anyone else.

I agree with CG on the loose - if I'm still the same number when I get to the end as I was when I started I honestly couldn't care less how many place holders there are.  And, controversially, I even couldn't care less if money has exchanged hands.  Doesn't affect me....not my money.

To be honest, the only thing that annoys me about paying someone to get up at some ungodly hour to be at the front of the queue is that I didn't think about doing it.

I may just start up a business using little children queueing up at day seat queues all over London for a small fee. I'll be like the Fagin of London's glitzy West End. Obviously without the rampant theft.

I don't see a problem with two friends playing tag team in a day seats queue. I've done it with a friend both in London and in New York and it never caused any trouble. One of us gets to the queue early and makes sure to inform the people who arrive afterwards that a friend will come and release her at a specific time. It doesn't make a difference in the number of tickets sold as we are still getting two. I don't mind if someone in front of me in the queue does the same.

On Broadway it is indeed quite common for friends to do this. I'm not a fan of paying someone to hold your place in the queue. But if it's friends who are simply sharing the time spent in line then I'm cool with it.

Yes, I have a London-based theatre buddy who can get into dayseat queues much earlier than me. We always make it clear that she was going to get 2 tickets anyway when I join 90 minutes later with tea.
(That's the deal - she gets there early and I get the tea.)

I think others already explained the difference: Dayseats/Rush Tickets are cheap tickets aimed at fans who can't afford good seats at regular prices. Correct me if I'm wrong but I think the whole custom started at Rent on Broadway, which had a very dedicated young fanbase and offered the first two rows in the stalls for a very low price every day so that the fans could see the show several times, bring friends along, etc. 

Based on my limited experience in London it seems to be mostly young people or elderly people in the dayseat queues, two groups that are not exactly flush with money most of the time. For them the dayseats are the only chance to see shows from close-up. I mean, yea, sometimes you can snag 10-20 pound seats in the Gods or something, but are far away. When a show is sold out or nearly sold out, all that's usually left are unaffordable top price or premium seats, so the cheap dayseats are the only chance to get in.

Now you get some well-earning visitor to New York City thinking "hrm, would love to take the missus out to (insert popular show) tonight but there are only premium seats that cost us $500 for two. I rather pay this bloke $100 to stand in line for $40 rush tickets for us. We pay $180, save $320, very nice, means a great meal with some expensive wine and a bit of shopping as well.  Money this person can easily afford but which pushes those out who can't afford any regular priced tickets and who could only afford the $40 tickets. Basically they are being priced out of one of the few options they still have.

This is getting a bit... well I'm not sure what word to use. If a reasonably well-paid 40-something person placeholds for their friend who's another reasonably well-paid 40-something person who shows up at 9am while their mate heads off, job done, is that still okay as it's not a business arrangement, or actually not 100% okay as they are depriving a young or elderly person of those dayseats?

And I'd contest that dayseats are intended for those who can't afford good seats at regular prices. They're certainly of appeal for those people, of course, but unless there's a specific scheme such as the Spacey Old Vic's under-25s front row one, they're there for anyone who strongly prefers front row and is prepared to put in the effort and queueing time, and they help keep a buzz going for that production.

I didn't think it was an argument, but anyway thanks for the insight.