Bonus Offer: Purchase and fly on Delta and Delta Connection® carrier marketed and operated flight segments into and/or out of Philadelphia/PHL, Phoenix/PHX or Charlotte/CLT between March 17, 2008 and April 17, 2008 and earn triple bonus miles for First Class travel (F, A fare classes); earn double bonus miles for Economy Class travel (Y/B/M/H/Q/K/L/U/T fare classes). Other codeshare flights are excluded from this offer.
Just to clarify, I can book this on NWA (using a voucher, woohoo) and still be eligible for the promo, as long as the flights say "Operated by Delta as DLxxx", correct?