Congratulations!  You just found my little unknown guide on how to write a review on a product you just purchased through eBay.  This isn't a full on English lesson or the end-all-be-all in review writing, but it'll atleast give you an idea on what's expected of you.  When I go to a product review, I want to know as much as I can about it.  It's strengths, weaknesses, brief backround, simple facts, examples by comparison and whether or not it's worth the purchase (without actually saying "buy this! or don't buy this!" if you can avoid it).   

Let me start off by showing you what not to do using an example.  A reviewer is writing about a movie he/she just purchased and only says  "great movie with awsome story glad i bought it".  Not only is the grammar and spelling wrong, but it's biggest flaw is it's lack of description.  It's not telling us anything.  This isn't like leaving feedback, you have 3,500 characters at your disposal, so use them. 

Than there is the format of your writing.  You'll want to keep it in small to medium paragraphs.  Once a reader see's a wall of text before them they'll immediately get turned off.  A typical review is approximately 3-6 paragraphs.  Each paragraph should start off and end on a subject or point being made.  Never continue it into a new paragraph.  That's not to say you can't have multiple ideas going on in one paragraph.  Wrap it up and move on. 

Everyone has their own style when writing.  For reviews I like to start off with some form of introduction, a type of orientation for potential newbies to the subject.   Than I delve into the meat of the review by describing the negatives and positives of said product.  I sometimes start off negative and leave it off with any remaining positives or visa versa, depending on my mood.  All while throwing in examples by comparison, facts and the occasional bits of humor.  The important thing is to let the reader relate to you, talking to them as if they were right infront of you. 

The remainder of the review is the conclusion or where I'm at with the product, if it was kind of bad, possibly giving it a last chance effort by saying something positive about it.  So if you're writing about a mediocre video game, you might say "...despite it's lack luster story, the gameplay was solid."  And if the product was really, really good, maybe even say something slightly negative to bring it down a notch.  After all nothing is perfect.  Keep things dynamic.

Lastly, after submitting your review, go back and read it again as if you were some interested eBayer passing by.  That's how you'll find all your mistakes and trust me, you will find some.  Infact this my fourth go at editing this writing.  Hope this guide helped and if you liked it, please mark it as "helpful" below.  So good luck and get writing!