I would hazard a guess you could make 99.5% of transactions with EFTPOS in NZ - the exceptions might be a few vendors at farmers markets (most take EFTPOS), sausage sizzles/ad-hoc fundraisers, fruit honesty boxes on the side of the road, etc. Maybe only 85% would take credit/debit, though.

From my experience in sydney/melbourne more places take credit/debit than NZ but also more places are cash only. Not as much penetration for EFTPOS.