What are some alternatives?
When comparing Mailbook and Landing Pages by Viral Loops, you can also consider the following products
Ship - Fast, native issue tracking for software projects
Landing Pages in MailChimp - Easy to build, custom landing pages for free
Carrd - Simple, responsive one-page site creator.
SaaS Pages - 900+ Screenshots of the best SaaS landing pages
Viral Loops for Startups - Virality for startups made easy 💪
Cruip - Free landing page templates for startups