The recommended Growth Model for your brand is…
Ads – Landing Page – Emails – Social share

For you, I’d recommend a paid ad funnel that gets your ad payment back ASAP and then turns happy customers into advocates to bring in more customers.
Ads
You have a low-cost offer which should be quick to sell if you get it in front of the right audience. As such, you can recoup your ad spend quickly while growing your list of customers.
Run ads that target your users where they hang out. Lead with a compelling offer in the ads that links to your…
Landing page
A well-optimised landing page that explains the key benefits and helps reduce the risk of purchase is needed here.
Follow tried and tested templates for your industry. Be sure to speak to the transformation the offer provides and make sure you remove any objections around risks the user might identify.
Emails
With their email captured, you can nurture them and get them to take further actions such as sharing on social, buying again, or simply getting some feedback.
A simple follow-up to let them know more about their purchase will build trust, and can be used to facilitate the above actions.
Social share
Once you’ve built trust and know the user has seen the value in your offer, ask them to share their experience and/or opinions (if they like it) on social media to expand reach.
In my experience, the key element here is the landing page. A lot of brands can massively increase sales and conversion rates through their landing page.
I’ve spent a lot of time writing, optimising, and improving landing pages to help my clients increase customers.
If you’re worried your landing page isn’t cutting it, check out our landing page audit service where you can get pointed, specific advice on how to improve the conversion rates of key sales and landing pages.