Hi Cristina,
The guarantee is the the outcome or result they want. AND depending what the outcome is, when I do a discovery, I manage their expectations. I know that they will get results by coming to our training or do coaching, if they are my target client. Yes it does come up in conversation, and what I say is.. “we only work with people that want to get results and are willing to do what ever it takes.” In coaching this is easy because they sign a contract that state the result are on them doing what ever it take in terms of tasking and taking action and we as coaches will work with them until they get result. We we put it out there when we are doing the discovery, that we wont work with you if it is not a good fit. Same things goes for training.
Hope I answered your question
If now let me know:)