Vendors are more likely to deliver better product to you if they perceive that their relationship with you is long-term and mutually beneficial in nature. There is no better way to show your vendor that you are serious about doing business with them than by visiting them, or having them visit you. Seeing a vendor on a regular basis also allows you to ensure that your company's quality standards are not being ignored or forgotten. Vendor visits are quite simply invaluable and having me spend a few days every quarter at your vendor's factory, or even just spending a day with a him/her, may pay huge dividends for you.