Brand Focus
Keeping your brand identity focused on one thing can make it easier for your product to take off.
Facebook started as a simple social network and now encompasses a marketplace, groups, and several other features.
Spotify started as a music streaming service but is now expanding to podcasts.
Disney pioneered animations and later expanded to theme parks and merchandise.
Start with the one (excellent) product so people know what your brand is about.
This will also help maintain your focus and prevent you from biting more than you can chew.
Once your product takes off, you can evolve, experiment with other ideas, and decide where to go next.