They have actual months that are "Click it or Ticket" and it is usually advertised when this is so people should know they are on the prowl for them.
There are certain Officers for certain things... most Departments will have so many Officers to patrol and to take calls that may come in and then they have "traffic" Officers, and that is their main job, TO DO TRAFFIC STOPS.
A lot of times if they pull someone over for no seatbelt, they end up getting a lot more tickets out of them such as: no insurance, suspended driver or plate, or even a warrant... sorry but the people that are driving with all of that going on deserve a few tickets, if not a trip to jail.
There are Officers out there that actually like writing tickets but trust me... most of them do not like it and they think about the hardship it may put on someone BUT.... THEY ARE DOING THEIR JOB!