Originally Posted by
freeice
hi all!
thanks a lot for those good hints! So far as my experience, I can't even upgrade to Finnair's Silver membership on my current flights because of this 50% counting. But changing to AA program sounds a bit crazy since I may never fly with AA.

The beauty of the AA program is that while the have the 4 segment rule they do not enforce this. And even if they would, it would only matter for status which you won't achieve anyway.
You don't need to fly the carrier of your FFP. There are many people here on FT who have membership with airline which they never set foot on.