Originally Posted by dancyn4
I like to buy a coach ticket and upgrade it to business class using miles.
Originally Posted by alik19
The only downside is complementary international upgrades never occur even as a top tier elite (i.e. like UA's systemwide upgrade certs). You can always upgrade using miles, but eligible fares are restricted.
Exactly. Internationally, CO requires very high fares/copay/more miles than the competition. Basically, CO is not a good carrier for the traveller trying to travel cheap and upgrade.
Originally Posted by alik19
Domestically, CO also offers you free upgrades (no miles or stickers) if you are an elite and there is space available. Usually first come first served based on elite status.
As I addressed above, CO does not give very many free upgrades to silvers/golds flying LAX-EWR. Even Plats have a hard time on this route. On some routes your advice would be more applicable.