I'd look to transaction count relative to number of addresses. While it is possible they could move in tandem due to independent factors, it is somewhat unlikely. So far it looks like both point to increased usage, and anecdotal factors (bitpay/coinbase signups) seem to support that. The rate of growth is modest though, in line with historical trends rather than accelerating.
The network value factor lends the price attractor its parabolic progress during linear network expansion. Anything which is not a decline in adoption rate is massively bullish in the long run. Just a matter of time.