As it stands now, I suppose that most people would just sign up and wait.
The talks were not interesting enough, and the events themselves felt like glimpses some Twilight Zone universe where an on-stage chair-thrower screams "Recruiters! Recruiters!"
The Toronto Rails Pub Night has a very good solution to this problem. Their policy is that you can stand on a chair and make a short pitch at any time, but you have to buy EVERYBODY a round.
Those that aren’t interested in the pitch are usually happy to have their glass refilled, and the modest cost makes for a modest speed bump.
Buying a round also seems less cynical than paying a meetup organizer to pitch the attendees.
It's not like it's not there. Sometimes ad letters contain things. I've been given a kitchen knife for listening to a knife demonstration in a hardware store. Online we do get a lot of content and services even though it often doesn't feel like it is a good trade with all the tracking and security risks.
At the same time (maybe not online) it is a dark (grey?) pattern to guilt people into buying something. Or you might get junk you do not want in exchange for being annoyed. And often you don't get anything but annoyed, as with billboards or leaflets.
So would it actually be more ethical to consistently give people payment for paying attention to ads? (I know there are some projects, yes.) Especially considering that now the ones profiting (minus costs) are not the ones who have to live with it. How ethical is a for-profit ad business where people are exposed to it whatever they do? (This is a question of freedom in my book too.) Then again, if I got a beer for every pitch I can't avoid I'd be black-out drunk at all times..
</offtopic>
On both of those occasions the tone of the evening was pretty much "we have these recruiters over here, and those recruiters over there, go say hi and please give your email address".
The entire London meetup scene (at least the one I try to frequent) feels like it's densely populated by recruitment agency staff, to the point where techies and hackers are driven away ... unless the meetup is consistently exceptionally good.