Gotchas
The three comments the gate demands are star-rated product reviews, shown to other buyers as genuine experience alongside a "was this helpful" count. Unlocking your listing means publishing three ratings of products you have probably never used.
The free tier gives no backlink at all. Their own feature list prints "No Back Links" next to it, and the link is sold as "Lifetime BackLink" on the $9/month tier.
The only route to the form is the Submit Your Tool button on the pricing page, and that button silently does nothing when it fires: no navigation, no request, no error. The destination is /onboard, which you have to type yourself.
The $0 price on the Standard Listing is flagged as a limited-time offer against a $15 list price, so the free lane is not promised to stay.
The three likes are separate from the three comments and are just upvotes on the listing cards, so half the gate costs nothing but a click; it is the review half that has a price.