Each budget row has to take its turn at the block, facing cuts and comparisons. Each program depends on a champion to defend it. Managers who have to defend their programs in front of their peers are going to take ownership. If nobody defends a program, cut it. Consider publishing detailed assignments as part of a plan, listing each program along with its owner, for all other managers to share.
Milestones are dates and schedules.
As you plan for marketing activities, be sure to include starting dates, completion dates, and milestone dates along the way. Every activity in the plan should be assigned specific times for specific points along the way. Unless you have a date for a milestone, you can't follow up on it, and you can't tell when it is behind schedule. Measurement starts with ownership and milestones, so you can measure tasks by dates of completion. That alone is not enough, however.