You picked two great consumer categories for this current era of consumer startups: CPG and Fintech. Both have transactional business models that can grow into large revenue businesses without large audiences (and keep you a bit under the radar from Facebook, Google, and others). If you have 10 million customers as a social network or an ad business, you’re likely doing less than $100 million revenue / year and probably unprofitable. In contrast, Charles Schwab does $8.6 billion annual revenue with 10 million customers. Transactional business models work far better at small scales (and I’d argue at large scales too!).