There was a YC company in W12 called Grouper that basically implemented all of the grab-bag of ideas. It was a 3-on-3 blind date at a pre-determined spot. Each person had to pitch in $20 to participate, which meant $120 revenue for each date. It seemed to be going well - I wonder what happened to them.
I loved Grouper. Met a lot of cool people and had a lot of fun. My guess is it was an operational nightmare to scale. There was a lot of manual effort on Grouper's end in selecting the venues, matching the groups, making the reservation, and paying for the first round of drinks (the model was you pay $20 per head to Grouper but it covers your first round).
This is the problem with these technology companies: they either provide whatever their app does for free and do who knows what with your data or they make you pay something crazy like $20 and you still don't know what they're doing with your data.