A service campaign (sometimes called a service action) is something that Skoda (or other manufacturers) may want dealers to do to a car to make it run as promised, avoid break downs or repairs or to repair or avoid a problem they have detected).

 

You can go to a Skoda dealer, give them your VIN and they should be able to see if all relevant "service campaigns" have been done on your car.

 

(Note - don't confuse this with a recall - it is similar but in the case of a recall, it could be described as a "mandatory service campaign" due to safety issue.)

Or you can ring Skoda Customer Services and they can tell you. 

I bought a 2011 1.8TSI in April. Changed jobs in July and now doing 25K a year. Will stick to 10K fixed servicing though. Cars only done 24K now. Had 15K when I bought it.