It seems like my DVDs have been taking more time to get turned around the past few weeks with my Blockbuster account, so I emailed customer service about it. In their second back-and-forth with me, they revealed this little nugget: "If an item is reported, returned or checked in on a weekend (including Friday,) then the next expected business day for a new shipment would fall on the following Tuesday, with limited shipments on Monday."
Now before they'd insisted they email DVDs Monday thru Friday, but for the past three Mondays when I've been owed a DVD or two, they haven't shipped them until Tuesday, so I get them Wednesday night. They advertise most DVDs take 1 business day, but that hasn't been the case lately for me. So I asked them why shipments are "limited" on Mondays, and we'll see what they say.
To their credit they sent me a free rental coupon after my first complaint.