I worked at Adecco USA full-time (More than 3 years)
I had two long term assignments from Adecco, each lasting 2 years, one of which led to an offer of permanent employment within the field of Psychiatry.
Weekly pay, option to be reassigned if the assignment didn't work out, gained more experience in a different field of medicine.
I applied through an employee referral. I interviewed at Adecco USA (Mountain View, CA (US)).
Interviewed directly onsite with 3 Google managers in succession. 10-15 minutes each with a very standard procedure. One was happy, the other was neutral, and the other played hard to get. Simple stuff really. Just adjust your interview corresponding to your audience