Early chip leaders in MTT's--how?

[JGlo]

Forgive me if this is a newbie type question, but I want some theories on something in MTT's that I have yet to figure out. I have been playing online for about 9 months and have had some success at the MTT's. The best I have finished is 4th in an 860 man $5 tourney on PokerRoom and various other times have placed in the money. I have always read and taken the advice that in the MTT's, you try to survive, play tight the first several rounds and then loosen up your play later on.

What amazes me is that (at least in the $5 and $10 MTT's) every time, after about 30 minutes, several people already have anywhere from $8,000 to $10,000 in chips, and we usually start with 800 or 1000.

The question probably shows my inexperience, but I would like to know what they are doing. Are they taking several longshot all-in chances because of the low buy-ins, are they getting lucky, are they just that much better than everyone else? Is it like this in the $100 and up MTT's? Just curious to the different opinions. Thank you for any response. [img]/images/graemlins/grin.gif[/img]