Favorize launched on Product Hunt in September, 2015. It got 119 upvotes on launch day. Yoni Shechter wrote more about the experience at The step-by-step guide to totally blow your startup’s Product Hunt launch.
They finished the day with 27 new users and 610 page views. After a week, Favorize had 136 total upvotes and 39 total new users.
It’s worth reading the case study as they tried a lot of different techniques as part of their campaign. They did get some criticism for tweeting at Product Hunt users.