Not only are there differences over the definition of relationship strength, but also about its antecedents, elements and consequences. For example, Patterson and Smith (2001) and Bove and Johnson (2000) suggest that relationship commitment arises indirectly from relationship duration – the longer the relationship, the greater the commitment or loyalty on the part of the customer. In contrast, Hausman (2001) argues that the long-term survival of the relationship is a consequence of relationship strength. A comprehensive model of the causes, components and effects of relationship strength cannot be developed from the literature. However, it is possible to identify a list of factors that are commonly associated with strong relationships. For planning purposes, these suffice as criteria for assessing relationship strength:

Economic content: as identified by Donaldson and O’Toole (2000), economic content is perhaps the most easily applied measure of relationship strength. In view of the fact that mutuality is an important part of relationship strength, care must be taken to ensure that measures are taken on both sides of the relationship. It should also be remembered that economic content of a particular relationship should be assessed relative to that of the party’s overall portfolio of relationships – hence a supplier must take measure both of share of turnover devoted to, or profits arising from a particular customer, as well as the share of the customer’s spend devoted to the relationship.

Interaction: besides the hard cash and resources that flow between the two parties, an important indicator of relationship strength is the amount of contact between customer and supplier. Such interaction may take many forms, depending on the nature of the relationship and the sector. Bove and Johnson (2000) offer contact intensity, confining this factor to the quantity of interaction between the two parties. Hausman (2001) and Zineldin (1996) add qualitative elements, such as the openness of communication and the nature of institutional interfaces. Patterson and Smith (2001) note that interaction can take the form of social bonds as well as business transactions.

Loyalty, trust and commitment: loyalty, trust and commitment are key requirements of any long-term relationship. Loyalty is often taken to be synonymous with relationship strength (see for example Patterson and Smith 2001). It has been grouped here with its antecedents in view of the fact that all three are very strongly associated with relationship strength, but would be difficult to obtain reliable quantitative information about in a commercial setting. Inferences can be made, however, by observation of customers’ buying patterns, complaints information and other feedback.

Alignment: this term encompasses a range of characteristics relating to the ease with which the two parties interact – the fit between the corporate or individual personalities of the two parties. Hausman, for example, observes that similarity of internal relational norms (i.e. similar expectations of the other party regarding values and behavior) between two parties is likely to contribute to relationship strength, whilst Bove and Johnson (2000) identify the importance of the customer and service worker’s interpersonal orientations.

Relationship history: obviously, the history of any dealings between the two parties should be carefully reviewed in order to provide the information needed to make judgments on the criteria. Care should be taken, however, to interpret the significance of any past conflicts in the context of the relationship conditions at the time. Jap and Ganesan (2000) note that conflict often increases with mutual interdependence, and can therefore be a feature of strong, mature relationships. Relationship duration in itself is also associated with relationship strength – the longer the relationship, the stronger it is likely to be.

Consumer vs business-to-business markets

Although much of the work referred to above is based on business-to-business markets, it should be noted that these criteria for measuring relationship strength apply equally well to consumer markets. Measures such as share of customer and behavioral loyalty can apply to individual customers as well as corporate buyers. In some cases, reinterpretation is needed. For example, in business-to-business relationships, considerable scope exists for different forms of interaction, at various levels of the organization, and with different levels of formality or institutionalization.

In a business-to-consumer environment, there is less scope for complex interactions. Nevertheless, Bove and Johnson (2000) stress that it is important to identify the number of different service workers with whom a customer interacts. Strong relationships with the organization are characterized by frequent interaction with a range of service personnel.