Thanks for the question! Our first channel was the Chrome Web Store because it was completely underutilized (high traffic, low number of good apps). Since then thats changed and its been less and less of an important channel for us.
Our biggest channel is word of mouth, and it’s not surprising - our passion is building a good product and our customers tend to tell others about that. Another thing we spend a lot of time on is product led growth (although it wasn’t really called that when we started!). Specifically we offer some free tools (Email Tracking, Mail Merge, Share) that can all be used independently of our CRM, are more focused and are all free. The idea being we give away some free tools to attract new users, and some of those users eventually discover our CRM and convert to paying users. Approximately 10% of our current paid users were just email tracking users first before using our CRM. We have a really poor user flow from these tools to our CRM so we’re investing a lot more here (better flows + more tools).
We’ve also recently started looking at paid channels. Podcasting, SEO, SEM, LinkedIn, Twitter… all the usual suspects. We’ve found some pockets of profitability but we’re def in the early stages and haven’t scaled any channels yet - more of an investigation!