Mostly this is the life cycle of bux sites. Bux sites average will survive from one week to 3 months. Max bux sites will survive for a year, unless they turn to bux.to schemes (also depends on the number of fools).

Person A says: Hello, I am A. Here is my site [link]. Fast payment (~3 days), low payout ($1-$3), many ads (7+), all self sponsored of course.
Person A is very helpful and active in all forums.

Two to four weeks later...
Person A: Payout now increased ($5-7), standard members will be paid within 15 business days. Bot factory now works 24/7 and produces "clickers" with a good average.
Person A is still helpful and active in forums.

Two to four weeks later...
Person A: Payout now increased ($10), standard members will be paid within 30 business days. Bots are not so active "clickers". Some limitations may be announced.
Person A is not so helpful and active in forums.

Two to four weeks later...
Person A: Sorry it is not my fault (but members' fault who didn't invest their life savings, or site was "hacked"), I cannot run this site anymore. Health problems, busy in "real" life, college, exams, family member died etc is a reason which will be given. Site is for sale or gone.
Members cannot contact Person A...

Person A changed his name to Person B.
Person B says: Hello I am B. Here is my site [link].............

This is the life cycle of a bux site in most cases. This scenario of course cannot cover all cases. Many bux sites opened and closed at the same day, while other "dead" sites were up for months even if all members stopped investing!