Ad Hoc is Pre-Paid Support
Example: Buy 5 Fireballs. Use one or two for telephone support. Keep two for a monthly healthcheck and keep another aside for emergencies.
Facts!
A FireBall is one hour support time.
Totally flexible, use for any support issue
Budget your IT spend in advance
Cost
Buy FireBalls for a low cost.
5-20 FireBalls cost just £50 each
25+ FireBalls cost just £45 each