Strong relationships are crucial to service industries as it reduces customer churn. This paper investigates the impact of relationship antecedents on relationship strength and its subsequent influence on attitudinal loyalty and share of wallet. Results from a structural equation model that utilises data from 591 consumers across nine different service types show confidence and social benefits, frequency, duration and relationship investment (driven by management and communication efforts) enhance relationship strength. Relationship strength drives attitudinal loyalty and share of wallet, with attitudinal loyalty mediating the relationship between relationship strength and share of wallet. This study investigates the factors that drive strong relationships and the importance of attitudinal loyalty as it mediates the relationship between relationship strength and share of wallet. This is the first study to simultaneously examine relationship benefits, investment and the frequency and duration of a relationship impact on relationship strength; and its subsequent influence on attitudinal and behavioural outcomes, in various service industries.