Fiverr

If you need support for anything from design and data analysis to research, report writing and pretty well anything else you can think of, you may want to check this site out.
The way it works is that you either post a job (a brief of what you want) and invite proposals or you research a specific freelancer (they have categories you can use to filter) and you contact someone directly to invite them to support you with some work.

This is a great option for things you might not do very often but need expert support for. The quality of freelancers and work can vary so do check out their reviews carefully.
I've had very good and not so good experiences depending on the job. I would use a freelancer from Fiverr for things like data work, research and design but not for what I would consider 'business critical services'.
In terms of value for money - excellent on the hole, it depends on the freelancer you select (and of course the more they charge, usually, the better they are).

Definitely worth checking out.