The purpose of Work Experience
Ultimately this will entirely depend upon whether you are still at school, at college, university or currently unemployed.
All work experience / temporary employment that you manage to attain as part of a course (or at any time) should, and in fact will, contribute to and complement the skills and knowledge you need for your qualification. The truth is that you should also consider temp work as part of a career planning programme, even if you may fundamentally work in a completely different employment sector or job later on. The commercial acumen and employment understanding will prove vital. It will make you stand head and shoulders above your peers when it comes to finding the job that you really want.
You will be picking up ideas, learning skills and gathering experience that will be useful to you in the future (even if your experience of temping is disappointing - the beauty of temping is that you can up sticks and try working in another part time job almost immediatley). You will also be able to add aspects of your experience to your CV and these in turn will assist applications for employment at a later date.