Coming back to reviewing products, a one-star with a single word is much more valuable than a random one star that lacks the motivation behind it. Simply saying 'D.O.A.' (dead on arrival) gives a better idea of why you marked the product so low. Now in this specific case, labelling something as dead on arrival invites failures from other quarters (such as a shipping issue), rather than the product itself, but at least someone reading through the list of reviews would be able to consider (or discount) those three letters and factor it into their own decision making process.

It's not particularly helpful to someone reading about a product, but if there is a high number of faulty units that are shipped, then a buyer might reasonably assume that there is a defect in the product itself, or the way the product is packaged. Yes, again, this might be more a problem of the seller, and might unfairly tarnish the review scoring of the product, but at least there is an extra piece of information that the buyer can assess (that would otherwise be lost).

Finally, I'd like to cover junk reviews. I'm counting fake reviews as junk, because they serve no purpose other than to manipulate the algorithm, either in favour of a company, or against the competition.

Junk reviews themselves don't necessarily have the stated goal of algorithm manipulation, but may do so anyway out of a shear act of weapons grade lunacy. These are the 1-star ratings alongside "great product", the reviews clearly destined for other products, or the reviews that fall into the fanboy category (1-star because "lol, it doesn't run Android, wAy To PrOmOtE VeNdOr LoCk-In Micro$haft!!!!!").

I have genuinely seen a review for a client's business that read something along the lines of "excellent service, would give them 5-stars any day" followed by a 3-stars. This forced the customer down so far that their Google Maps placement was outshined by the previous lease holder who was marked as "permanently closed". It mirrors other such reviews that I have come to automatically flag as junk in my mind when reading through things (like 4-star with 'Excellent!' as the review – what constitutes 5-star? Does it need to be hand delivered by the messiah himself?)