The biggest biases typically come externally in the form of monetary or near-monetary compensation for bias. This might be someone being paid as a sales person to promote the products that they are available to sell, commission structures would take this to an even more acute level. Someone paid to do sales might face two of the strongest biases: monetary (they get money if they make the sale) and ethical (they made an agreement to sell this product if possible and they are ethically bound to try to do so.) These are the standard biases of the “seller’s agent” or sales person.