When they drop them in my area, they go very quickly. I check the job board very often when they are about to post and have seen all of the most desirable jobs get snatched up in a matter of 15 minutes from when they release them.
It's like a feeding frenzy!
If I can get 2-3 of the ones I want, I would consider that a good month. I already look at the shop rotation rules to make sure I'm good to go and assign it as quickly as possible. Sometimes minutes count. I have hit refresh after a few minutes and 1/3 of them are taken. If you miss the initial offerings, you still have another chance when people flake and those rare emails are sent during the month for shop it right away offers.