Can any AA member tell me what the advantage is by booking an EVA flight as an AA flight number. A friend is insisting I do it this way but can't tell me why.

Thanks,

it's the only way to get aa credit. and any flight with an aa number will be treated from a mileage perspective as if you were on aa metal

keep in mind that often times the AA codeshare is significantly more expensive than booking the EVA flight outright, so effectively you would be paying the difference just for the miles...

This matters if you're an AAdvantage member. Your profile doesn't say that you are. If you expect to fly BR (don't ask me how they came up with that code) a lot, you might want to join their Evergreen Club.

Or, you might look into what other partnerships and/or codeshares they have in case one of them is more useful to you than AA miles. (Unfortunately, Star Alliance bases credit on the operating carrier, as opposed to OW which bases it on the carrier whose flight code is on your ticket, so getting UA credit might not be possible even if you find a *A code-share.)

A third option would be to find another airline, ideally a *A member, that flies to wherever for a reasonable fare - but you've probably already tried that.

Since when AA partners and/or codeshares with BR???

Correct me if I am wrong, to best of my knowlege, Cont., All Nippon and UNI are BR's partners that you can earn/use credit mileage.

I booked directly through BR last year and wasn't able to credit AA. Ended up crediting CO.

You are partially correct. AA does not "partner" with BR. However, AA does codeshare with BR, and, as stated by flybud123 above, that is why you need to book the flight as an AA codeshare in order to get AA mileage credit.

However, it is not entirely like flying on AA metal, since codeshare flights do not qualify for certain promotions, such as DEQM -

"Flights operated by our codeshare partners or oneworld� alliance carriers are not eligible for this promotion. "