Let's say you work for an architecture firm... I don't see a lot of architects taking potential clients to play golf or on hunting trips. That's why I asked if it was industry-specific.
I do business development for a construction company and frequently get free lunches from engineering companies and suppliers. The engineering companies are usually more conservative, just a lunch here at there at bar & grill. Sometimes a happy hour. Suppliers are the ones that can go all out. If you order enough product from them, they will spend big bucks on you. One of our estimators had a supplier fly him to Alaska for fly fishing. I used to know a guy that worked for a engineered products supplier who did this as his job. All he did was take big wigs and "important" people out on hunting/fishing trips, sports events, fancy dinners, etc. It sounds fun, but I think he did a lot of grovelling which I wouldn't tolerate.
Some companies put caps on it, though. A friend of mine at another big construction firm once had a supplier offer him an all expenses paid trip to see the Masters tourney in Augusta. Management squashed it, though. There was nothing illegal or unethical about it, just the managers feeling like it would create dissension among the ranks.