<font face="Verdana, Arial, Helvetica, sans-serif" size="2">Originally posted by gleff:
Read and re-read these offers!
THe DL promo in question was 10k with first purchase and then 10k more when you spend $5k in 5 months, plus the standard 5k for the spending = 25k total for spending $5k.
I did a similar (fee-free the first year) deal on the DL Business Amex... 10k with signup, 5k for adding two fee-free cards, then 5k for spending $5k in 5 months for a total of 25k including the regular miles for spending. Took a few reads to realize what I was dealing with!
There's a lesson in here for all mileage promos.. not just the DL Amex ones. Before spending money or making decisions, know what you're getting.
In my case I knew what I was getting and wasn't spending money. So it was a no-brainer.
Unfortunately, with too many promos, even the CSRs for the offering company don't understand the deals! 
On the one hand, it would be nice if promos were more clear cut.
On the other hand, the more convoluted a promo becomes, the greater likelihood for loopholes... 
</font>