The author, a serial microstartup maker, shares their experience of reaching a daily revenue goal of $500 with their microstartups, which took 3 years to reach $300/day but only 4 months to reach $500/day. The business model is a mix of app sales, subscriptions, affiliates, and ads. The author spends only 10% of their time maintaining and fixing bugs. The microstartups have seen significant revenue growth, with one reaching $50K/year and another reaching $117K/year.