who or which?

[keannu]

Is this "who" possible in this phrase? We've learned "who" is for people, while "which" is for things or animals, but I've seen exceptional cases as well. I've seen "which" describing people, but rarely seen "who" for things, but I think it's possble.
Is this for "personification" of the company giving out things like humans or some other reason?
The earlier version of this workbook contains "who" but in the later version, it was corrected to "which", which implies the editors might have made a mistake in the earlier version.

ex)The word "free" is a powerful marketing tool. Giving away free information and free samples is common these days. This is because marketers know it is likely to attract a lot of attention. At first glance, this strategy may be hard to understand, because it seems that companies who give away things for free are losing money. However, in the long run, these giveaways are sure to earn the companies profit....

[5jj]

You worry too much.

We can think of companies as 'people', so who is fine.