There is a saying in business that you should always use your own product or service. Someone who works at Ford probably does not drive into the parking lot at work in a Toyota and vice-a-versa. Using your own product or service is a vote of confidence. The same logic applies to those services for which you are an affiliate. Using the services you promote through your affiliate links is both a vote of confidence in the services and can provide powerful outlets to promote the product. This is especially true if the service you are promoting is a marketing service.
For example, if you are an affiliate of an Email Service Provider (ESP) you could actively use the service for your own email marketing needs, and include a link at the bottom of every email you send out promoting the service through your affiliate link. If one of your subscribers gets an attractive email newsletter or promotion they may be compelled to click on the affiliate link and sign up for the service. Those purchases can add greatly to your recurring revenue stream.