This study assesses the relative contributions that different demand segments make to a reduction in seasonality at tourism destinations. Specifically, we ask which types of markets are the most effective for counter-balancing seasonality in high seasonality-prone coastal destinations? This is particularly important where there is a significant presence of ‘non-market’ based segments, such as social tourists, as in Benidorm, Spain. The study integrates different statistical techniques to compare the relative effectiveness over time of four different groups (Imserso travellers, other domestic, the UK and other international) on the seasonality of demand in Benidorm. Using 10 years of accommodation data, we analyse trends in counter-seasonal effects of each segment through significant economic events (the Global Financial Crash and Brexit). The results confirm that both Imserso and UK travellers reduce seasonality in Benidorm. However, the analysis shows varying magnitudes and the specific effects that each segment exerts on seasonal variations, which has implications for destination managers when selecting strategies for market development to reduce seasonality over time.