I can't comment on conversions with both a free version and non free, but I can comment on just a landing page optimized to sell. With very targeted traffic com

I can't comment on conversions with both a free version and non free, but I can comment on just a landing page optimized to sell. With very targeted traffic coming from a recommendation such as a positive blog or a glowing youtube review I've seen conversions of up to 20%. Very specifically targeted traffic without reviews (or what one might be called a pre-sell) can get up to 8% conversion, but that's if your software solves a really specific issue and you've got great copy hitting the benefits you will offer and a good funnel urging people to buy. If you're just getting people who are only vaguely related to the problem you're trying to solve, you will not even see 1% conversion. This of course depends a lot on the price point, target audience, and most importantly source of traffic. If you're getting very targeted traffic and you've got a great landing page emphasizing the benefits, you will see better conversions if you're not hitting those points.