If you shop much on Amazon, the chances are that you've checked out a few reviews before making a purchase.
If other customers have had a particularly good experience - or a terrible one - it can help you make up your mind. Generally speaking, it's not something you'd do for entertainment.
Some reviews, though, are downright hilarious. We look at a few of the best.
Hutzler 571 Banana Slicer
"This is so convenient since my family hid all the knives from me. You stab one person and suddenly you can't slice your own bananas anymore."
"As shown in the picture, the slices is curved from left to right. All of my bananas are bent the other way."
"This is much faster than my guillotine, easier to clean than my table saw and much quieter and cleaner than running my chain saw in the kitchen. I don't how I've lived without this!"
Tuscan Dairy Whole Vitamin D Milk
"I thought I'd save a little money on this product so I clicked on the 'Order it used' button. Boy, was that a mistake! When new, this product is just fine. When used, it's almost undrinkable."
"This is a fine milk, but the product line appears to be limited in available colors. I could only find white."
"Someone has answered my gentle prayers and FINALLY designed a pen that I can use all month long! I use it when I'm swimming, riding a horse, walking on the beach and doing yoga. It's comfortable, leak-proof, non-slip and it makes me feel so feminine and pretty!"
"I was disappointed to find that only one fifth of the pens I received were pink. Or, maybe more, I can't do maths."
"I can't do it! Are you sure these are for women? They seem very complicated."
Box Canvas Print of Paul Ross
"Don't buy this picture. It looks fine on the website, but the one they send you is upside-down. My wife hasn't stopped crying for a week."
"If you only buy one 20 inch canvas print of Paul Ross this year, this is the one to get."
"I recently purchased this poster, and while it's lifelike, well made and had a certain, portly charm to it, I have since found out that it's actually cheaper to hire Paul Ross to come over and stand against a wall, whenever you feel the need to look at him."
The Holy Bible: King James Version
"For those of you who don't know, this is God's second novel after the Old Testament. It's a marked improvement, in my opinion... That said, there is still vast room for improvement. Plot wise, there isn't really much suspense, and the story can be incredibly repetitive."
Wenger 16999 Swiss Army Knife Giant
"I tried to file my nails, but in the process I accidentally fixed a small engine that was near by. Which was nice."
"All functions and features work well. The electron microscope, while damaged, still needs alignment, as it doesn't magnify nearly enough, but it did discover water on Mars, and with the pulse generator/sampler was able to discern the salinity, however due to the shipping damage the saline content is inaccurate."
"I've always wanted to own a pocket knife that was too large to fit in my pocket and here it is!"
"I don't know if this is a scam or if mine was broken, but it doesn't work and I am still getting abducted by UFOs on a regular basis."
"Works as advertised, insofar as that goes. But I recommend you DO NOT put two of these near one another. I'm still trying to find the rest of my house, and I still can't get the cat out of the wormhole's event horizon."
Aluminium Foil 18"
"This is amazing. It's like paper but made of metal. METAL for gods sake! They call it foil, dunno how they make it, probably magic or by a blacksmith with a massive hammer. And all for less than the price of a train ticket to Blackpool, probably."
"I love this product, I've used it to wrap around most of my belongings (phone, shoes, car, cat) and now everyone thinks I'm well rich because I own loads of silver things. It even got me a wife."
Playmobil Security Check Point
"This toy would be a lot more realistic with about 350 people standing in line for an average of an hour. It still makes a nice set with the interrogation room."
"I was sadly disappointed to find that the first time I combined it with the Calais Illegal Immigrant set, the scanner failed, and I now have 8000 unregistered aliens in my child's toy box, claiming asylum. Please rectify."
Veet for Men Hair Removal Gel Cream
"Excellent product. Most prisoners confessed within five minutes of the first application. Can recommend."
"On the positive side I can report the following unexpected benefits: my pain threshold has almost trebled. I can now pass urine in three positions: standing, sitting and curled in a ball weeping."