In my opinion, if a company requires you to sign a contract they aren’t worth your time. As a business owner I understand protecting my investment, but sadly part of a business is sometimes getting taken advantage of by dishonest people. If the company you hire is reliable and does a good job, I believe you’ll keep them and recommend them. I believe you should ask for a summary of what their service will be for you on a weekly basis so you have something concrete to refer to.
At Alpha Omega Pools we offer great service, and require no contracts.