In every client interaction, you are usually selling something. Based on you closing all these conditional sales, the client eventually gives you the coveted PO and buys your product/service.
It is important to set expectations and objectives very clearly ahead of every client interaction. A set of expectations should be set for yourself and a bit conservative estimate should be reserved for your management as well, which is usually waiting for the sales closure.
For a typical product/service sale situation, here are some sample conditional sales that a sales person will have to go through
1) Customer accepts to receive more information from you, shares his email and other information
2) Based on information sent by you, customer accepts and commits to spend more time on a more detailed conversation/meeting regarding the product/service (to understand)
3) Based on the understanding of what you offer, customer shares his current concerns, problems that he is facing and gives you an opportunity to solve his problem
4) Based on your response (RFI/RFP) or demos, customer agrees to share more data, that will make the solution more relevant to his needs
5) You submit an estimate/price proposal and gain conditional acceptance from the customer to find out if it is as per his expectations
6) Negotiate to close the gaps and eventually close the sale.
A lot of sweat and efforts will go in every step, but it is good to warm up your client in every interaction and enjoy every moment of sales success (in every conditional sales). After all closing a sale is a tough job and expecations are very high.
All the best !