Sadly right now the only 2 surefire ways. Is bot delegation and delegation contracts to people who pay you for your sp for certain amounts of time periods. Thought it will take away from your RC's and you can't really curate depending how much you delegate out.
Some are delegating out and keeping enough to earn from the sidechain tokens.
Sadly those are the only real options the community has.
RE: Asking The Investment Community: Is There Any Way I Can Turn 25k SP Into $20-30 A Day?