There are a few guides around telling you how to spot a fake from the packaging and etc. But for that you actualy need to buy an item. What im writing is just to give u tips before you buy.
* Nearly all sony magicgate memory sticks on ebay are counterfeit
* Fake 2g and under usualy work fine.
* Fake 4Gb,8gb and 16gb are where the problems working start.
* Only buy from UK/USA/Canada/Australia
* Be wary of sellers selling more than half a dozen sticks in thier items for sale and have a feedback of under 180, sellers with higher feedback usualy are there to get good feedback and will not risk seller fake items for which they will get negative.
* Just because a seller claims item is located in the UK does not mean it is genuine, 99% of them get their stock from Asia
* If a seller sells alot of memory sticks of the same gb then you know its counterfeit
* Ebayers seller counterfeit memory sticks sometimes prefer bank transfer. This is because they cannot use paypal because they have scammed alot in the past.
* Sellers who have high amounts of items in a buy it now auction are of course selling counterfeits. Why would you list 50 memory sticks exactly, also noting they accept bank transfer, and they do not sell anything else apart from say 8gb memory sticks(notice these sellers only stay on ebay for under a month before dissapearing)
* Mark 2 versions are being counterfitted, again only buy from the countries as above and follow the rest of information in this guide.
* To play ps1 games on a genuine/conterfeit 8gb you need the popsloader patch(google it). Many people believe thier genuine sticks are fake when they cant play thier ps1 games but that is not the case,
I have been checking out memory sticks since 2006, generally you will be safe purchasing a Sandisk memory stick. Fake memory sticks are not worth it. They Rarely work 100%, dont have the capacity they say, they screw up and freeze your computer. If your the person who wantsto put Iso's and homebrew on your memory stick for psp then anything 4Gb and above it will barely work.(some games show up, others dont)
a Genuine seller is 1800memory, they are located in australia. Their prices are cheaper than retail. Cheapness is not worth it when it comes to memory sticks, i have a 4gb and 8gb which are useless for the psp. you will end up binning it and buying a genuine one. Yes i got an 8gb for a bargin £26 when it came out. again games show up or dont show up, and apps that used to work dont work.
If your buying a large capacity memory stick for iso's and homebrew then i suggest you buy from 1800memory, even reviews from buyers at amazons american site are posting negative saying that the memory sticks dont work. and for some reason the prices there for sticks have gone ultimetly cheap. That is a worry, i was planing to personaly buy from there until i checked out the reviews and noticed plenty of negatives for the 16 and 8gb sticks, which seem to have gone 40% cheaper than last time i checked?
anyways safe bet 1800memory on ebay for memory sticks 4gb+, or sandisk ones. Yes they cost more but they wont give you problems. From what i wrote in my guide, these counterfeit sellers only sell memory sticks, they sell huge amounts, they sell for low prices, some refund buyers(but expect you to leave positive so other buyers dont know they are non working sticks).
hope you found my guide usefull, thanks for reading.