Originally Posted by ExplorerWannabe

Because United would like to get the $1000 or so of revenue themselves or give the upgrades to loyal customers (many of whom spend a lot more than $12k per year) who follow the rules instead of having that seat go to a non- or low-status customer who bought the upgrade cert on the Internet and deprived a higher status customer (who is also spending a lot of money annually) of that upgrade. Let's flip that equation: Why would a person who can afford enough travel to amass over 1M award miles endanger their status and account for $1000? That's right up there with someone owning a high-end sports car driving miles out of his/her way over a bumpy dirt road to avoid taking a toll road.