I've become an expert in this type of thing over the years. I can usually tell where a band comes from purely by looking at what's in the package (without looking at the stamp, obviously

)
Examples...
British bands are usually the worst. A CDR with no artwork, maybe a hastily thrown together bio if you're lucky. Maybe a pic taken by the band's uncle (he's got a camera, so he qualifies..). Terrible production. Probably sub-Metallica shite or stoner nonsense.
Russian bands always wrap their stuff in brown paper tied with string. Always a hand written note inside (good manners, these Ivans)
Finn bands tend to go for a very pro look all around. Good production, photography, artwork is usually there from the very start.
US bands send photcopies of every single piece of press they ever got, usually in a custom presentation folder that must cost a fortune to produce and mail. US bands also like those old-school promo pics, with the logo and contact details printed on there too.
Italian bands tend to have no shame when it comes to dressing like an ass. Most favour the heavily made-up "futuristic" approach, meaning they inevitably end up looking like a cross between Mad Max extras and the Village People.