Getting customers?!

Hey all officially launched my pokemon card collection app a couple days ago. I had 17 people on my waitlist. I sent out an email to them when it went live. So far I have 9 people that have signed up for the app in about a 2 days. Most people have not used it much but I have had one user that has added over 90 cards into their collection for tracking. The rest of the users have signed up and then dropped off. I am curious to know how everyone else have approached their launch and how they have solved customer aquisition. So far I have had 0 people pay for the pro plan. Ill start to dive deep into the analytics to see what the customer behavior is and why they dropped off. What are other people's stories out there?