It's common to seasoned market people yes, but there are a huge amount of people who don't know these things which we assume are basic knowledge and get scammed.
You'd really be surprised on how many people fall prey to Skype impostors the number is quite high, they check only the display name and not the profile and get fooled.
Many new people to the market are also unaware about PayPal not covering virtual goods and getting charged back.
Yeah noted down the bit about adding a Skype button to avoid this problem, and I was going to link your thread too, I'll add that now.
Yah trust me i know alot of people get scammed from imposters ..... and this is a good thread not undercutting you or anything :P