Since the end of July I have never seen a “weekend” challenge. So it is impossible to get the “Working for the Weekend” and “Decathlon” as explained in the Achievement guide.
Once, at the very beginning after the Xbox release (maybe around mid-August), I thought I saw a banner ad in the “discovery flights” menu. But when I went to look in the flights list, I hadn’t seen anything particular and had given up.
I had then made the discovery flight in Egypt on Gizeh, and I had even landed in Cairo, but it hadn’t triggered anything.
And since then, I have never seen an ad again.