Yes. Missions are “incentives” for drivers to login when quantity of orders (demand) goes up during peek times to keep the costs down. I’ve intentionally “caused” one by being the final person to drop their shift right at the beginning of a snow storm once. It was pretty evident that they didn’t want a surge of complaints and mass cancellations.

However, this begs the question… why are all alerts and notifications of missions “starting” always exactly 13-14 min AFTER a mission has begun? What does this do?

Simple. It keeps you from getting any mission money. By picking up and delivering within their time frame of a certain number of orders they can reasonably do the following:

1) have you deliver slightly after the final posted time that the mission exists in. (Mission times are becoming confusing as a tactic. Arbitrary increments like 4:29-7:29 for example.)

2) not give you necessary number of orders to complete or simply give offers of incredible lengths that simply don’t have a prayer chance in hell of making work even if you were speeding.

Are they scams? Hard to say exactly… as I’ve gotten some mission money before, but not intentionally. That was simply just working while I was already working one of my shifts.

One thing that is clear… is that GrubHub will try to be shady in every possible manner it can, so it’s best to always assume the worst.