The number of trial days (7, 14, 30, 60, 90, 365) is arbitrary. The only downside to a longer trial period is that it creates a lag between the time a user first starts using a product and the first payment date. This lag is the ONLY reason to not offer a long trial period. Arguably, the longer the trial period, the greater the chance of acquiring and retaining a customer. This is why nowadays, every mattress company offers 365 day trial periods. The more a customer uses your product, the more dependent they become on it, and the less likely they are to switch to a competing product.
In this case, with a 7-day trial period, Wappler is losing a lot of customers who on principle, refuse to pay for the product before they’ve had the chance to fully evaluate it. Extending the trial period to 14 days would help. Extending it to 30 days would be even better. Extending it to 365 days would be better yet, but as I mentioned, this would create a one-year cash flow gap, thus it’s unrealistic. Also, the marginal rate of return decreases with each extension of the trial period. Thus, 14 days would be a lot better than 7 days, 30 days would be better than 14 days, but not as much of an improvement as going from 7 to 14, etc…
Your statement that “14 day trial should be enough” begs the question, enough for what? It’s certainly better than 7 days, but almost certainly not optimal in terms of maximizing revenue.