Ethics: Make use of a free trial knowing that you're going to cancel?

I do this frequently. And sometimes I've kept the service. They offer the teaser in hopes that you will like the service. They know a lot will cancel and that's built into their business plan. I don't think it is an ethical issue. You don't owe them anything. They offered you something to try. You tried it. If you need a service to use in the future, you will go back to them.

I have tried free subscriptions to just about every credit reporting service out there and I don't like any as much as the free ones. No guilt about canceling any of them.

I kinda disagree. If someone has worked long and hard to help you, the least you can do is support their job a wee bit. The whole "the workman is worthy of his wages" thing. In this case, I'd keep the service maybe a month or two, consider the $7.99 or $15 a "tip," and then cancel (unless you find yourself actually using the service). Yes, I know tech support won't get any of that money (unlike wait-staff or housekeeping, who you can tip directly), but the company may keep records of who helped which customers, and whether that customer stayed the the company for any length of time, so the techies might get brownie points or something like that.

A better "tip" for the technical service people who helped you would be to write a nice letter about them to the company (mentionning them by name if possible).

That said, I think it is an ethics issue and the only reason businesses have built all those trial cancellations into their business models is our society's declining ethics. Retail stores' prices have factored in loss from shoplifting - does that make shoplifting ethical?

The intent behind a buisiness offering a free trial to their services is to convince you to buy their product/service. If you enter into the trial knowing you will absolutely NOT buy the product/service, no matter how impressive it is, you are abusing the offer. If a conversation had been required for you to sign up for the trial, you most likely would have had to lie, or at least dance around the truth, as to your intentions. And that, right there, tells us it is unethical.

But there is no real correction for your unethical behavior. Signing up for a service you do not intend to use, just because you feel guilty does not erase the behavior. Nor will it lower the costs to those people who trial in good faith and chose to buy (the real losers in your scenario). Learn from the mistake, try to consider your behavior before you act, and do better next time. You will also probably recommend this company if you ever run into anyone looking for fax service.