As per my 3 years of experience it's all about conversion rate, and private feedback of buyers (Private feedback: When you accept order as buyer you have a option to give review to seller that is politically visible and we see on gigs, but after 2-3 days you get notification to give feedback in private to the seller that is not visible on public/gig but fiverr use it to adjust position of your gig on search )
Just what i think, but not a fact : )