Email Contact Importing

A programmer built a viral growth engine by creating a birthday reminder service that leveraged email contact importing, turning a failed dynamic address book concept into a massive user acquisition success.

Key Points:

• Initial Product Evolution:

  • Started as a self-updating address book concept
  • Pivoted to focus on birthday reminders after noticing user engagement
  • Created Birthday Alarm.com as dedicated service

• Viral Growth Strategy:

  • Built reciprocal sharing: Users share their birthday, then get offered to save others' birthdays
  • Created viral loop: After adding one birthday, users prompted to invite friends
  • Achieved initial growth to tens of thousands of users without marketing budget

• Growth Optimization:

  • Simplified user experience by:
    • Adding pre-written invitation messages
    • Including copy/paste buttons
    • Creating one-click email sending

• Technical Innovation:

  • Built one of first email contact scrapers for Hotmail
  • Allowed users to import entire address books
  • Feature survived 20+ years across email platforms

• Results:

  • Grew from zero to 100,000 members overnight after implementing contact scraping
  • Scaled to approximately 100 million members over time
  • Proved sustainable growth through email contact importing