How we research

This is the page the rest of the site rests on. “Independent” and “honest” are the most crowded claims in this category — half the sites competing with us use one or the other in their strapline. Asserting it again would be worthless. So instead of claiming it, here is the method, in enough detail that you can check whether we follow it.

Where our facts come from

Every statement on this site about a subscription's price, trial, eligibility or contents comes from that company's own page, and we cite the page. Not from a press release, not from another review site, and not from what we remember being true. The pages we check against are listed on every article that states a term, and they are:

• Audible Premium Plus: Audible's own membership pricing block — last checked 11 August 2026.
• Kindle Unlimited: Amazon's help page, Understanding the Kindle Unlimited Subscription and Benefits — last checked 11 August 2026.

What the “verified on” date means

It is the date a person last opened that source page and confirmed the fact was still stated there. Not the date the article was written, not the date the site was deployed, and not a timestamp that moves on its own. If a page says a term was verified on a date, that check happened.

This matters more than it sounds. Prices in this category change, and a page that quoted a figure two years ago looks exactly like one that checked yesterday. Without a date, a price is not information — it is a rumor with a dollar sign on it. Dating every check is the cheapest possible way to let you judge how much to trust a number, and it is genuinely rare: none of the competing sites we surveyed during research published one.

What we do when we cannot verify something

We leave it out and tell you we left it out. We never estimate, never average, and never carry a figure across from another site to fill a hole.

There are real examples of this on the site right now, and they are the best evidence that the policy is genuine rather than decorative:

• Audible Premium Plus: How many credits each plan includes per month, and how long an unused credit stays usable. Audible's public pages did not state these in content we could retrieve, so this site does not put a number on either.
• Audible Premium Plus: The size of the listening catalog. Catalog counts are marketing figures that change constantly and we could not confirm one against a dated source.
• Kindle Unlimited: The monthly price. Amazon renders it in JavaScript on the signup page, and the Kindle Unlimited Terms of Use did not state a figure in the content we could retrieve. We are not going to print a number we could not read on an Amazon page, so this site shows the price as something to check at signup.
• Kindle Unlimited: The length of the free trial. Amazon's help page confirms a trial exists for eligible customers but does not state how long it runs, and the length has historically varied by account and by promotion.
• Kindle Unlimited: The size of the catalog. Amazon does not publish a figure we could confirm, and it states that the catalog changes at any time.

A site that wanted to look authoritative would fill every one of those gaps with a plausible number. The reason we do not is simple: if you planned a cancellation date around a trial length we invented, you would be charged, and that is our fault rather than yours.

The break-even method

We are not able to tell you a subscription is good because we used it for six months. What we can do is arithmetic you can reproduce, which is the honest substitute:

monthly fee ÷ price of one book you would otherwise buy = books per month to break even

That is the whole model. It is deliberately simple, because a calculation you can check on the back of an envelope is worth more than a sophisticated one you have to trust. Two things it does on purpose:

• It uses your numbers, not ours. We do not publish an “average audiobook price” because we have no sourced figure for one, and a made-up input would make every result wrong downstream.
• It counts books finished, not bought. Audiobooks in particular get abandoned, and a credit spent on something you gave up at chapter three has bought you nothing.

The calculator is driven from the same verified-terms configuration as everything else on the site, so when a price changes the arithmetic changes with it. There is no stored table of results to go stale.

What we have not done

We have not listened to the catalog. We do not run a testing lab, we have not compared narrators, and we are not going to tell you a production was excellent, because we would be making it up. Everyone in this category implies they have heard everything. We have not, and saying so plainly is more useful to you than the alternative.

What we have done first-hand is read the terms — including finding out how hard some of them are to read. Audible's detailed plan pages redirect into an Amazon sign-in. Amazon's Kindle Unlimited signup renders its price in JavaScript. Those are real observations about the process of finding out what these services cost, they are the reason for several of the gaps listed above, and they are genuinely useful to a reader who is about to hit the same walls.

Independence

We are paid a flat fee when someone starts a qualifying free trial through our links, and that is the entire business model — there are no sponsored placements, no paid reviews, and no free products. It also means we have a financial interest in you subscribing, which you should know while reading anything here.

The check on that interest is structural rather than a promise: several pages on this site recommend a public library card, which pays us nothing, and at least one comparison regularly concludes that you should not buy either subscription. If those pages ever quietly disappeared, you would be right to stop trusting the rest. Full details on our affiliate disclosure and editorial policy.

Telling us we are wrong

If a term on this site is out of date or a figure is wrong, tell us and we will check it against the source and fix it. Corrections are made promptly, the page's review date is updated when they are material, and we would much rather hear about it than have it sit there. Email info@shelfandsound.com or use the contact form.