Fixed Spot vs Run of Day (ROD)
What's the difference?
Fixed Spot advertising guarantees your ad airs at a specific, predetermined time on a radio or audio station. You book 10:30 AM on Monday, and your spot runs at 10:30 AM – no variation. This gives you absolute certainty about when listeners will hear your message.
Run of Day (ROD), also called Run of Schedule (ROS), gives the broadcaster discretion to air your ad anytime within a defined daypart (breakfast, drivetime, evening, etc.). You pay a lower rate, but lose control over the exact broadcast time. Your 30-second spot might run at 7:15 AM or 8:45 AM – the station decides.
Why this matters for UK media buyers
Choosing between these options directly impacts your campaign budget and targeting precision. Fixed Spots are premium – you're paying for certainty. ROD is cheaper because you're offering the broadcaster scheduling flexibility, which helps them fill unsold inventory efficiently.
In UK radio, where drive-time slots (7-10 AM, 4-7 PM) command premium rates, Fixed Spots during these periods cost significantly more than ROD placements in the same daypart. For time-sensitive campaigns (same-day offers, event promotions), Fixed Spots ensure your message hits the right moment. For brand-building campaigns, ROD provides good frequency at lower cost.
When to use each
Use Fixed Spots when: - Running time-critical promotions (flash sales, limited-time offers) - Targeting specific dayparts with proven audience patterns (breakfast for commuters) - Competing in crowded categories where positioning matters - Your message requires coordination with other channels
Use ROD when: - Building awareness over extended periods - Working with tighter budgets - Frequency matters more than exact timing - Running longer campaigns where flexibility increases overall reach
Practical considerations
Many UK media agencies blend both approaches – booking Fixed Spots for peak times when precision matters, then filling additional frequency with ROD at lower cost. This balanced strategy maximizes impact while controlling spend.
Booking lead times differ too. Fixed Spots typically require confirmation 2-4 weeks ahead on commercial stations like Capital or Smooth, while ROD placements often book closer to air date. Always confirm with your station contact.
Note that some premium stations or sponsorship partnerships may only offer Fixed Spot options, while smaller stations often favour ROD to optimise their schedule.