Gabe might eat the servers they are hosted on.

I just delayed HL3

Maybe they give a limited ammount to control the market?

I guess it just means you don't get a card every time you vote...last time I voted it said something like I already voted 5 times, so next time I vote I'll earn a card

Maybe you can only get half the types of available drops?

The subject to availability line is not about the cards but the games. It's a discialmer for the rare occasions one of the games being voted on is not available in your country.

Probably it just means level <5 people won't get cards & you'll only get cards every 3rd time you vote.

How ever, be fast, so u dont have to think about it.

It says "restrictions apply" because you have to be level 5 and above to get them.

you get one every 3 votes (if your at least steam level 5),

if you become steam level 5 later on before the summer sale ends, you will be given all cards you were meant to receive previously - steam (when you vote 5 times this pops up)

I believe you get a card every 3 votes, at least that's what I read.