The FTC regulates the laws and rules surrounding how one has to disclose your relationship with a business, product, or organization. Advertisers have had to deal with this for decades when they pay celebrities to endorse their product in TV or radio commercials or magazine ads. The internet has changed the game because today anyone can create a blog for free and write about products and organizations. It no longer takes big money and time to become a media outlet. Everyone is a publisher.
Because of this sudden surge in this new form of media the FTC has had to craft rules specifically about how bloggers and other internet publishers have to disclose any relationship with an advertiser or company. A relationship can be defined as about anything. If a company gives or lends you a product to review that is a relationship that must be disclosed. If you stand to gain anything like a commission by reviewing or promoting a company or their product that is also a relationship that must be disclosed.
Optionally you can include a notice next to any product endorsement with your disclaimer. Most bloggers find that the easiest way to disclaim your relationship with an advertiser is to create a separate page on the site called “Affiliate Disclosure.” Disclaim on that page that any links to external pages could be affiliate links and make sure the Affiliate Disclosure is visible on the site without having to scroll down below any given product endorsement.