I posed that question to DL (via e-mail). Do they really read what people write to them? Their response did not help at all. Here is what I wrote:

[I received, and signed up for, a targeted promotion. "Fly One, Earn
Now"

I am a bit confused by the terms and conditions:

"Purchase and fly one or more segments at any fare on a qualifying
flight between November 15, 2004, and January 31, 2005, and earn 10,000
bonus miles in the Delta SkyMiles® program."

Clearly I need to FLY on Delta between those two dates. Does a ticket
purchase PRIOR to 11/15/04, with a flight after that date, qualify for
this promotion?

Thank you]

I thought the question I posed was pretty clear. Here is DL's response:

[Thank you for your e-mail to Delta Air Lines.

You would need to enroll is this promotion and take a qualifying Delta
flight between November 15th, 2004 and January 31st, 2005 for the
bonus.

We appreciate your interest in Delta Air Lines.

Sincerely,

Kelli Skylark
Online Customer Support Desk]

Clear as mud. I am guessing that someone at DL was being funny. Look at her last name