Is there any sort of auditing or quality control for subtitle files added to your database? If you are able to review, edit, and 'certify' some premium subtitle files that might be a reason to go premium. You could offer one free premium subtitle download pack for every free user.
What do you have in place for usage tracking in your app? Do you find that users download the same subtitle files in multiple languages? If you have some usage tracking in place it'll be easier to see what some trends might be.
Sam's suggestions are good and I think testing what constraints or premium experiences you can tease in the product experience itself can lead to some increases in conversions.
My advice would be to A/B test the copy on your premium page. I'm not a user of your app (but I understand what it does) and the way you describe the premium benefits just don't feel too compelling. Some small copy changes could result in increases in conversions.
Some social proof (pictures of customers with testimonials or even just testimonials) about how much better the service is with premium could really help.
Also, I hope you're already using analytics to determine how many people click on the "Get Premium" button but who don't complete the purchase. My sense is that the multi-point purchase plan might be leading to fewer purchases. You might want to experiment further with fewer plans or a fixed plan.
I have been building and selling digital products online for almost 3 years. I have tested and re-tested many models of pricing and found what works and what doesn't.
Here's my thoughts on your issue:
I would say that you need to determine what your goals are. Are you trying to get the most users, or are you trying to get paid users?
I took a quick look at your page and I had a hard time even finding what or how to upgrade my account, and when I did find the page, I was not given any incentive to upgrade at all.
I would remove all the places where you say 'It's Free!', because although you do have a 'lite' version with no-cost to try, the product itself is a paid product. This not only will enhance the value of your paid product, but will also greatly increase the value of what your are giving away for free with your 'lite' or trial account.
I feel that you need to define who you are selling to and what it is they are getting in return and then you need to ensure that there is clearly stated and obvious value to upgrading.
I am more than willing to jump on a call with you, should you have any further questions or if you'd like to get together and build a more effective sales funnel.
Displaying Ads will be better if you ask me. But you must also note a few things. A large top-of-funnel demonstrates that value and attracts more visitors, which leads to more trial users and eventually more buyers. Publish lots of great content where everyone can see it and offer many different types of content as well to appeal to a wide variety of potential users. For example, slides and videos appeal to visual learners and make content fast and easy to consume, while eBooks and white papers provide detailed information and allow users to consume the content at their leisure. A 2012 study by software conversion firm Totango found that within Software as a Service companies surveyed, those that did not require a credit card had twice as many paid users after the first 90 days. To increase paid subscriptions, you want to get more new users onboard as fast as possible, but sign-ups from visitors who never intend to buy are useless. So, it is important to focus on getting the right new users to sign up. If you offer a freemium or free trial, some users are already predisposition to buy from you. Your goal is to help these users understand the full range of your product’s capabilities and value, so they do not want to go back to living without it or investigate the competition. Nurture potential users. Potential users may buy from you eventually, once they realize the true value of your product or become so dependent on it that upgrades and add-ons are worth it. Your goal is to nurture these users so that you are already top-of-mind when the problem you solve becomes more evident or painful. The time limit adds urgency, and the nature of the trial is transparent, putting users in a buying frame of mind. However, because users have only a certain amount of time to try the product, this model requires some nurturing to keep conversions high. “You need to not only walk them through your product and show them how it all works and make sure their engagement is high, you also need to be emailing them with tips, tutorials, testimonials, videos, anything that will convince them to come back and USE YOUR PRODUCT. That keeps your best features paid, but it is hard for users to fully grasp the value of your premium product, so they are not sure if it is worth paying for. When testing a freemium subscription model, you want to make sure your model fits your product, industry, and ideal customer.
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath