Your business should have one specific "North Star" metric.
Absolutely everything you are doing as a startup should be done toward growing your North Star metric.
This requires a singular focus. To help you maintain the required discipline, use the "SMART Goals Framework".
For example, suppose that your goal is to grow your site to 100K monthly uniques.
S - Specific: 100,000 unique visitors
M - Measurable: Use Google Analytics to measure
A - Attainable: Use scientific method to prove to yourself that you can get there; otherwise, adjust the numbers.
R - Relevant: Increased usage legitimizes product placements.
T - Time-bound: ~30 days. You need a by-when date. Parkinson’s Law: Work expands to fill the time available for its completion. So without a time-limit, there is a risk of scope creep and watering down of the goals and results.
This is an iterative process. From one SMART goal to the next, you will get better at setting SMART targets and hitting them!