I understand "subscribe" in this context to mean "sign your name underneath in endorsement," rather than the sense we use for subscribing to magazines or tea of the month clubs. I don't think it says one thing or another about depth of faith.

I'll answer this from my experience. When I began my journey towards faith I gained cognitive functions and information processing abilities that I didn't even know I was missing. At the same time, my life began to become easier as events and situations seemed to smoothly break in my favor. Nothing outrageous, just small, repeated wins. Correlation, causation, coincidence? I live in constant paradox. Ultimately, I choose faith.

They have subscription fees. They call them donations or tithes though.