That's one of the indices. If you're going to be a speaker or you have some formal function, then it's fine for you to attend the event. If you're invited to attend an event, which quite often will be a gala or something, and if that ticket is paid for—and it could be quite an expensive ticket—by a company that's looking for something from you, then you shouldn't accept it. You should be on your notice, whatever the value of the thing, as soon as somebody who is looking for something from you wants to give you something—I would stay away from it.
On February 19th, 2015. See this statement in context.