I participated in one of the 'spend promotions' that Barclays put out last year. Mine was for Oct/Nov/Dec spend on my Miles & More credit card with Barclays. The goal was to spend $750 each month. That's what I did and had heard anything from them in the meantime.
But today (exactly 8 weeks after the end of the promotion) the miles finally posted.
I just hope they'd do these promotions more often 🙂