I did one internship, between freshman and sophomore years of college, over 10 years ago.
My overall experience was pretty good. The work wasn't quite aligned with my field (I am a software engineer, and they had me doing technical writing, no actual software development), but the experience has helped me in my career, as part of a senior software engineer's job is to write technical specs.
I don't know that I contributed to the company on a company-wide level, but I certainly contributed to my department.
I feel I gained some "real world experience". College does not adequately prepare you for the realities of the corporate world.
IIRC, I got the job by interviewing through my college's career office. The internship lasted about 12 weeks. I received no benefits.
Hope this helps.
