Making custom email segments is annoyingly difficult. Emailing “users who logged in last week who aren’t paying customers” would require a lot of setup on existing platforms, if it was possible at all. Palabra allows you to merge all your users' data from websites like Stripe, Mailchimp, and Intercom and easily make specific segments to email people. Karen, now working on Atlas (heyatlas.com), has gone on to raise over $5M from Hi VC, Pioneer, LAUNCH, 2048 Ventures, First Row Partners and others.