What are your thoughts on BYOB?

If you are invited to a big outdoor party and the host is providing top sirloin, sodas, water, plates, cups, utensils, kayaks, rafts, games, etc, and you are asked to bring a side dish and something to drink, do you keep your beverage in a separate cooler or put it on the provided drink table for all to share? Do you take what you brought when you leave, or leave it at the party?

If it matters, as the host I spent around $500 and had 50 pounds of all-natural, grass fed, aged top sirloin from a local ranch. (It was a gift to me from the ranch, valued around $800 and it was all eaten yesterday.) There were about 75 people that came and went. There was no shortage of anything and all had fun.