Conflicts of interests have been hypothesized when agricultural advisory services are connected to agri-input businesses. However, these have not been examined using large sets of advisory service and grower data. We provide quantitative insights into dependencies between service, crop production, sustainability and the level of agri-input business-linkage of extension workers. We analyzed 34,000+ prescription forms (recommendations) issued to growers in China, as well as grower interview data. Results revealed some conflicts of interest, but to a small extent and not always as expected. Both forms of advisory service (with and without business-linkages) heavily emphasize chemical pest management. However, grower interviews revealed that business-linked advisors recommend pesticides even 18% more often than non-business-linked advisors do (96% vs. 78% of advice). This advice was also often implemented (94% and 90% uptake). There is a slightly higher chance that dangerous pesticides are being recommended by business-linked advisors (0.4% vs. 0.14%), but these advisors recommended antibiotics less frequently (1.6% vs. 2.5%). No effects of the source of advice on yields or grower profits were found. Thus, there is no apparent economic disadvantage of growers taking advice from business-linked advisors. However, if pesticide use is a concern for human health and the environment, then the increased use of such products may further exacerbate existing problems. Depending on national priorities, countries may re-consider moving away from governmental extension services, and more closely analyze the advantages of promoting agri-business-linked advisory services (no public funds, better outreach) versus the disadvantages (slightly higher pesticide risks).