Tips for moving PH engagement to product downloads?

Hi everyone! What are the best ways to get PH users to actually DOWLOAD your product? I'm planning a PH launch for my company, Sleek (https://www.onsleek.com/). After people engage on PH, I want to encourage them to download the Sleek Chrome extension... after all, what's the point of launching if people don't download the product! I'm thinking of a few different tactics: - referal deals for PH viewers (either a link or special code - which is better?) - referal deals for inviting friends - individual messages to each person commenting on my PH launch Any other suggestions??? Thanks!