Table 1 This table summarizes the major (more than one source) identified barriers and facilitators, structured along their domain and (sub-)themes. Findings with major support (5+ sources, 12.1% of total) are marked in bold

Outer Setting

Product supply

− Challenges in product supply (20–33)^±+, suppliers are unreliable (24, 30, 34, 35)^±+_, geographic isolation (34, 35)^±, demand fluctuations (30, 36)^±

Consumer characteristics

− High demand unhealthy products (20–24, 27–29, 31, 36–40)^±+, lower demand healthy products (20, 23, 33, 36, 41)^±, unhealthy products more profitable (20)^±, healthy perceived as expensive (23, 24, 38, 40, 42)^±+, customers prefer unhealthy products (23, 28)^±+, customers uninterested in health (23, 36, 40, 42, 43)^±+ and customers lack health knowledge (23, 42)^±+

Community relations

− Robberies and safety concerns (21, 40)^±

+ Strong retailer-community relations (23, 27, 31, 40, 41, 46)^±+

Competition

− Competitors steal customers (36, 37, 41)^±+

+ Lack of competition facilitates success (31, 35, 41)^±

Legislation

− Governmental taxes (59)^±

+ Health promotion legislation (46)⁺

Media

− Stocking follows media exposure (29, 34)^±

Inner Setting

Culture

(Commerce)

− Commercial interests (26–28, 30, 32, 33, 48–50)

+ Open for innovation and experimentation (24, 26, 31, 33, 47, 51)^±+

(Health promotion)

− Not feeling responsibility for community health (23, 27, 28, 31, 33)^±+, no affinity with health promotion (21, 31)^±

+ Feeling responsibility for community health (20, 23, 24, 27, 28, 33, 35, 42, 43, 47, 52)^±+, affinity with health promotion (27, 47)^±+

Structure

(Physical)

− Space constraints (27, 37, 40, 42, 45, 48, 49)^±+, limited storage/cooling facilities (21, 22, 28, 29, 34–36, 38, 40)^±+, store renovations (24, 26, 27, 43, 50)^±+

(Operational)

− Unhealthy products restocked by suppliers (21, 40, 44, 49, 54)^±+, inconsistent product stocking (24, 44, 53)^±+, supplier contracts (22, 38, 45)^±+, difficulties returning unsold products (17, 34)^±, constraints set by retailer (21, 27, 28, 49)^±+, campaigns (42, 45, 50)⁺

(Financial)

− Products go to waste (20, 22, 28, 30, 33–36, 40, 41, 44, 52)^±+, limited financial resources (42, 47)⁺

(Knowledge and capacity)

− Lack relevant expertise (23, 24, 31, 36, 42, 44, 47)^±+, limited time (23, 31, 42–45, 48, 50)^±+, staff turnover (26, 39, 50, 53)^±+

+ Applicable business experience (23, 28, 31, 47, 51)^±+

Practices

− Stock in small quantities (20, 22, 25, 26, 31, 33, 34, 37, 39, 40, 55)^±+

+ Flexible in establishing supply (30, 39)^±+, waste limitation tactics (20, 31, 41)^±

Actors

Personality traits

+ Pragmatism (31, 42, 51, 52)^±+, desire to help (42, 47, 51)^±+, tenacity (31, 51)^±

Psychological reactions

− Frustrations regarding intervention (29, 41, 42)^±+, psychological stress (27, 39, 56)^±+

+ satisfaction from positive feedback (25, 31)^±

Intervention

General characteristics

(context-intervention fit)

− Does not fit the context (28, 42, 45–47)⁺.

+ Fits the context (27, 28, 37, 39, 42, 47, 48, 57)^±+, fits customer needs (24, 37, 41, 45, 47)^±+, fits retailer needs (37, 47)^±+

(flexibility)

− Inflexible design (27, 37, 42)^±+

+ Adaption to context (30, 35, 37, 48, 52, 53)^±+, awareness of context complexity (27, 57)^±+

(complexity)

+ Simple to implement (42, 47)⁺

Components of the intervention

(support)

− Difficulties maintaining provided equipment (29, 48)^±, lack of intervention support (42, 52)^±+

+ Financing start-up and running costs (20, 22, 29, 35, 37, 44, 48, 52)^±+, provide promotion materials (28, 29, 42, 47, 52)^±+, monetary incentives (27, 37)^±+

+ Building retailer-supplier relationships (22, 26, 37, 40, 49, 55)^±+, subsidising stocking of products (20–22, 27, 31, 39, 49, 55, 56)^±+

+ Consultation regarding health promotion and business skills (24, 29, 35–37, 42)^±+, staff training (28, 35, 43)^±+

(promotion)

− Faulty placement materials (28, 52)^±, retailers refuse negative promotion (28, 45)⁺, insufficient (re)supply of materials (42, 52)^±+, materials lack durability (45, 52)^±+

+ High quality materials (24, 28, 42, 45, 47, 48)^±+

(staff training)

+ Improved engagement staff (35, 37)^±+, improved skills for implementation intervention (29, 35, 48)^±

(customer education)

+ Regarded as vital by retailers (20, 22, 37, 40)^±+, improved demand promoted products (22, 37)^±+

(pricing)

− Regarded as unviable and potential risk (23, 49)^±+

Costs and benefits

(costs and risks)

− High running-costs (21–23, 28–30, 33, 35, 37, 39–42, 44, 47, 49, 59)^±+, high initial investment (22, 44)^±, substantial time investment (23, 28, 29, 31, 42, 44, 53)^±+, substantial effort or impractical (28, 30, 35, 42, 45)^±+, commercial risks (21, 23, 28, 33, 37, 39, 56, 58, 59)^±+

+ Low or minimal effort (24, 27, 28, 45)^±+

(commercial benefits)

− Commercial benefits do not outweigh risks and costs (22, 28, 30)⁺

+ Increased profits and sales (22, 24, 26, 28–30, 45, 47, 55)^±+, more customers (22, 28, 30, 55)^±+, improved customer satisfaction (28, 30, 45)^±+, improved public image (28, 31, 45, 47, 55)^±+, establishment of partnerships (35, 37, 47, 57)^±+, general “positive outcomes” (27, 47)^±+

(health benefits)

− Doubts regarding changing customer behaviour (24, 27, 33, 42, 52)^±+, lack of observable impact (35, 45)^±+, loss of momentum (31, 45, 52)^±+

+ Health promotion is inherently valuable (20, 23, 24, 27, 33, 35, 42, 43, 47, 52)^±+, visible impact on sales and people (24, 28, 29, 35, 45, 47)^±+

Process

Engagement

− Unmotivated retailer (44, 52)^±

+ Commitment and support from retailer (24, 25, 27, 31, 42, 50, 60)^±+, retail-specific engagement strategies (22, 24, 37, 45, 48)^±+, providing staff training (35, 37)^±+, build engagement incrementally (35–37)^±+, develop intervention ownership (35, 37)^±+, culture and language sensitive approach (26, 27, 37)^±

Collaboration

− Collaboration with competitors (28, 42)⁺

+ Good relationships collaborators (21, 25, 26, 42, 48, 49)^±+, collaborative planning intervention (27, 37, 42, 44, 46)^±+, intervention helped developing collaborations (37, 47)^±+

Communication

− Poor communication between collaborators (31, 42, 45, 47, 50, 52)^±+, lack of clarity on goals and agreements (21, 47, 52)^±+, language and cultural barriers (21, 27, 30, 39)^±+

+ Clear communication (26, 27, 35, 42, 52)^±+

Organisation of activities

− Lacking planning and guidelines (42, 47, 52)⁺

+ Thorough planning and transparency (42, 51, 53)^±+