Difference between real memory cards and fake memory cards

Is there any difference between the genuine ones and fakes ones apart from the fact one is real and 1 is fake?
i just got a fake one from ebay,

in the information menu it says magicgate: unknown

 

Fakes have horrible writing speeds, they last less and some even don't hold their own capacity. Yours is fake since the magic gate is unknown.

 

Dont buy stuff like that off ebay is all I can say. Same thing happend to my friend.

 

i bought 2 fake ms from ebay very cheap.
of course i didn't know they were fake at the time until someone told me.
luckily, i sold them back on ebay even made some profit..

 

Great lol, now someone else will have that problem. But it's a good idea. (No offence American and UK and etc users are more trusted then some other places so people will buy thinking it's real. Could even be sold for full price... Wow