I played a game of Agora yesterday with Erik & Jaylene (who had borrowed my copy and played several times) and my wife Robyn (her first time). I'd played a couple 2-player games and one 3-player game before this.
Erik & Jaylene said that their strategy was to use each turn to block entrances or reduce the other player's income, which is especially important in a 2-player game, but we wanted to see how it would play out in a 4-player game.
We didn't have too many events for the first half of the game, so mostly it was just placing and blocking. The first few rounds all the cards were attached, and people tried to increase counters while reducing doors for their opponents. I had a 2-counter 4-door store that was reduced to a 3-counter 1 door store. Jaylene had a 3-door store that was completely shut in with another card.
At some point we explained to Robyn about placing a card not at an angle, but parallel but not touching another card, creating a narrow hallway that has to be closed off at both ends. It's not unstoppable, but takes two cards to do it. She took that, but then started adding other cards along the openings, and eventually had a bunch of branching hallways that would take too many cards to block.
Our scores were actually all over the place--at one point it looked something like:
But after a few fires and floods, things evened out a little bit. Unfortunately, we then realized that Robyn was only two turns away from winning, and had too many protected doorways that we couldn't get to. All we could hope for was to burn down some of our own stores in order to clear cards to get to her doorways ... but alas, we only got one fire in the next round.
The scores were very close, though, with all of us within one turn of winning. We did at least manage to keep Robyn from winning by too many points.
None of us played close to the table edge (which another friend tried doing) but clever placement of cards can have almost the same effect.