Yeah, teell all your friends . Buenos Aires is a special place, but theres other cities that are just as packed. London being one of them. The Manchester area is pretty packed as well if you count Greater Manchester and Liverpool. Lima Peru used to be this way as well but in the last 20 years they've really spread out the clubs around the country more(More like alot of them died). trying to do some more research on some of the smaller Asian leagues to se if there are any similar places.
Looking to do a lot more in the future including USA, Korea, Mexico, France, etc but it all depends on how well these do.
Book sounds very interesting will check it out.
Man.. in the USA you could get the USL.. there are like over 20 teams..
Then indoor soccer, there are a ton of teams there too (MASL I think). Couple those with MLS and you could fill in a lot of the country, even tho its geographically huge.
P.S. your posters are pretty cool!