Cryonics isn't a service you can just sign up for and forget, hoping it works out if you need it. That cryonics requires preparation, thought, and a modest ongoing investment of time in order to work out well - more so than an insurance contract - is one of the few concrete reasons we can point to for its comparative unpopularity. If buying the product involves work, fewer people will buy the product: simple and true. Cryonics providers are becoming better at helping their customers with these preparations, but like all serious medical procedures, there's a core set of arrangements and due diligence that no provider can take out of your hands. If you want it to work, you have to put in the effort.
Along these lines, here's a recent post from Michael Anissimov at Accelerating Future:
it’s easy to fantasize that if I happen to be hit and killed by a truck tomorrow, someone will quickly notice my cryonics necklace, call up Alcor, a heroic field technician will give me a heparin injection (to prevent clotting), quickly whisk me away to a hospital, where I am pronounced dead, packed with ice, and shipped to Scottsdale for an effective cryonic suspension. However, such a suspension would probably be considered seriously suboptimal. My blood would be clotted and my tissue would be swollen.
He goes on to discuss Alcor's standby program, one of the service-oriented improvements Alcor employs to encourage and ensure a good outcome for end of life arrangements. It can't help if you're hit by a truck when young and healthy, but there's no reason for an elderly and dying customer to suffer just as poor a cryosuspension when they could be attended by a standby team at the time of death:
Standby is the process in which cryonics personnel are deployed and waiting near the bedside of a patient at serious risk of death. The purpose of Standby and a Standby Team is to take prompt action to restore blood circulation, administer protective medications, and start rapid cooling when the heart stops beating. This is critically important to achieve a good cryopreservation.
Signing up for cryonic suspension at the present time is less like buying an invitation to an event, and more like agreeing to help organize an event. As time goes on and cryonics organizations grow and mature, I imagine this will change - but still, as I said above, does anyone go into a major medical procedure in this day and age assuming they will bring nothing to the table in terms of planning? It's just the same for cryosuspension. Ultimately, making it work for you comes down to your input to the process.