I booked a flight to Moscow a few months back from within Europe and the cheapest flight was Lufthansa at $260 . A beginner might think well it’s the cheapest so let’s book it right? not it’s a bad idea as when i checked the fare class it does not post any points to my united account … There was a flight with Finnair that cost $10 more but posts to american airlines at 100% so i chose that one as i would get around 3000 miles which i value at around $50 and clearly anyone will value them at at least $30 . It’s especially important to look twice if you are trying to get status with an airline! so this is my tip for you to always be careful.