People who promise to get us "top 3", real business or scam?

Hi people, I've got outreached since we get featured in "popular upcoming products" by Product Hunt experts promising to get us "top 3 of the day". Their promise is to use their own network to get powerful upvotes and comments. They ask to get paid only if they get us top 3. However, they don't offer any proof of what they did. Is that a legit business? Have you been contacted too? What's your opinion? (Please PH admins, don't ban me, I didn't sign the contract 😂)