Hmm, the question that needs to be answered for elite members is which miles are doubled? Elites receive a minimum 1,000 miles per flight segment, then a bonus of either 25% or 50% or 100% depending on status. If elites get a bonus equal to their minimum miles than this is big news. A MCI-STL-BNA roundtrip for $80 would yield:
4,000 status miles
4,000 bonus miles
1,000/2,000/4,000 elite bonus miles
1,000 online booking bonus
Pretty good to get 10,000 miles (in my case) for $80.