Not what you asked, but you thought about selling your projects? That would at least be a few million: ETFs would then make you quite a bit more than you make now.
Yes. 15K revenue or even profits per month wont get you few million. Having said that, I buy small software/saas products/companies. If you are interested in potentially selling, hit me up. Criteria is min $10k-$50k/month average revenue.
(solidaffiliate.com and AnalyticsWP.com are the two active projects)