You won’t get huge results in three weeks on a small budget unless you hit a viral gold mine, which means about the same odds as your chance of writing a bestseller.
Keep your finger on the pulse. There's lots of great commercially available (and free) software out there that can give you an idea of what people are saying about you. No matter what scale you're looking at, get used to using them.
You need to course-correct—don't just launch and leave. Watch how people interact with your program. Based on the metrics it is recommended you establish at the outset, determine if it's working. If not, iterate, change and revise. That's how you develop best practices of your own.