B2B referral schemes - do they work?

I've been toying with the idea of referral scheme and looking at "both sides" rewards so both the new customer and the referrer receive a reward.

Does anyone have any experience with regards to offering rewards to employees of existing customers? Part of me feels like there may be some push back around it but maybe I'm overthinking it.

I also question how well B2B referral schemes work anyway outside of the small business community. I've been looking at the GrowSurf website and most of their case studies are B2C and the one B2B I took a look at targeted small business owners (it was a bookkeeping service).

I have a customer with about 100 employees - are any of those employees going to generate meaningful referrals for me? Would they do it for a $50 gift card?

Thoughts and insight always appreciated.