Airlines are required to compensate customers when they’re bumped from an oversold flight, generally, giving 200 percent of one-way fare up to $650 for those who are two hours and 400 percent up to $1,300 for those four hours late.
Most customers don’t know this hence fail to get what they are owed according to OutsideOnline.com
What the airlines offer generally fall far short of what they are required to give.
For what it’s worth, airlines are not obligated to make up for other bad flight experiences such as weather delays.