It's been a little while since I ran a G2 review. When I did test response rates against GC dollar values, there was no noticeable change in response rate between $50 vs. $25 GCs. I was surprised, but glad to have some cost savings, haha
yea we have a lot of data on this since we drive hundreds of reviews off the back of our surveys - $25 is definitely the most common and generally the sweet spot. Agree $50 doesn't move the needle or at least diminishing marginal returns (certainly doesn't double conversion rate).
I like Sarah's angle of using a less common # as a bit of a pattern interrupt.
More specific swag (e.g. airpods) can also be more effective than giftcards, but you need some gifting tooling to make that scalable.
the coolest advocate incentive i've seen (this wasn't for a review more of a top tier advocate reward) was a Blackstone Grill in the summer which got my attention, haha