Apple in the US has launched a new feature on its online Apple Store - customer reviews, but only of third-party products.

The company is soliciting customers to write reviews, though only of third party products at present. Reviewers say their piece, and are asked to rate the products using a star system - five stars for best.

Apple asks reviewers (who must sign in using their Apple Online Store, .Mac or iTunes Music Store account) to explain their likes and dislikes on a product, focusing on their own experience. Other online retailers, such as Amazon, also offer customers the chance to review products that they buy.

Reviews should be limited to 300-words, and reviewers are asked to avoid single-word reviews, bad language, contact information and, significantly as the reviews appear on Apple's store, "alternative ordering information". Apple checks the review out for five days, and then publishes it, subject to a review adhering to the terms and conditions of the task.

Apple is offering little inducement to engage in the process.

"If you do submit a review, and unless we indicate otherwise, you grant Apple a nonexclusive, royalty-free, perpetual, irrevocable, and fully sublicensable right to use, reproduce, modify, adapt, publish, translate, create derivative works from, distribute, and display your content throughout the world in any media," the company says.

Apple insists all submitted reviews be original content, and that reviewers have ownership of the work they submit.

It's on Apple's decision not to invite reader reviews of its own products that discussion is likely to revolve around. On this, Apple says:

"What is the 5-Apple rating?
All Apple products have a rating of “5 Apples” because we think they’re great.
Why can’t customers rate Apple products?
Would you trust us to display less than perfect ratings on our own products? We didn’t think so!"

It's not yet clear if Apple has opened this feature up for all third-party products, or selected ones.