Pushbotting

Could someone explain this concept for me? From what I understand the idea is to push any two reasonable cards (reasonable being position dependent) when the blinds get high in relation to the stacks. Now, I don't know if this is just my stack, if it's everybody's stack, a combination of the two. How high is high? What would be considered reasonable cards for doing this? Is there a time to push any two? What should I do if there are 4 left with very short stacks in the blinds? I understand that I should probably get SNGPT, but I'm not completely sure of what the concept of pushbotting is, so I'm hesitant to drop 80 bucks right now. I tried what I thought pushbotting was and managed to bust out of 7 straight, many on the bubble, so I'd like to figure out what it is before spending the money.

I've tried searching the forums for this info. If someone can point me to some other threads where this is discussed, that would be great as well.

Thanks,
Will