How do we grow from here. Does spending money on paid marketing work for SaaS early stage?

Hello SaaS Founders, What is your best customer acquisition channel from where you get the most number of leads/customers? Has paid marketing worked for you initially? If yes, what are some ways to test whether a paid channel is working or not? What SaaS marketplaces are you listed on (if at all), and which one do you like the most? Any other advice on best practices or something that worked for you while growing from 1 to 10. (Have initial paying customer and now need to scale)