Don’t guess. If a prospect has a question you don’t know, it’s okay to say you have to check first. Here’s the tip from TerraCycle CEO Tom Szaky, “If you don’t know the answer, do not guess: People will ask you tough questions, and you may not always know the answer. The person asking you may be testing you, knowing the answer full well. And if you fumble, it’s very hard to rebuild credibility. Do not guess.”