How do I know if my problem is traffic or conversion?
Look at visitor numbers. Very few visitors = traffic problem (work on discovery and findability). Plenty of visitors but no subscribers = conversion problem (work on the page: clarity, photos, funnel length, price-to-proof match).
Does posting more content get more subscribers?
Only if your failing check is visibility — and even then, channels that compound (a findable page, an email list, collabs) outperform daily posting that resets every 24 hours.
Why do visitors leave without subscribing?
Usually one of four things: the promise isn't clear within seconds, the first photos don't carry it, the path to subscribe takes too many clicks, or the price asks for more trust than a first-time visitor can verify.