Essentially what the attacking team is trying to do here is to try and create gaps in the midfield by drawing Middles to either side of the pitch. This is generally used after hard driving to setup attacking plays and when you're in the defending team's half.
It's important that the Middle is kept interested and that the dump happens on the Middle. This puts the defending middle offside and creates opportunities for attacking plays.
It's important for the attacking player to time and angle their run. If the attacker goes too hard, they will lose the interest of the Middle and the Link will come up to make the touch, allowing the Middle to retire to an onside position. If the attacker is too slow, not much ground is gained and the defending Middle can run straight backwards. In either case, no attacking opportunities are created.
Tips for keeping the Middle interested:
Make eye contact
Some players refer to running a 'J' (or 'Ⴑ') in terms of the line that should be run