An affiliate disclosure must be immediately visible. Don't bury it as this defeats the whole object.

It should not be:

• in a footer
• in blocks of text people are not likely to read
• in hyperlinks (the reader may not click the link)
• on your About Us page or in a ‘terms of service agreement’.
• in a pop-up (it may be blocked) or only viewed when a button is clicked.

It should be:

• in the user’s field of vision as soon as they enter the website.
• visible above the fold, so users don’t have to scroll down to see it.
• placed as close as possible to the “triggering item” (e.g. an affiliate link).
• repeated if necessary. A single disclosure on the home page may not be enough because readers may miss it when they enter a site from a different location or travel through the site via a different path.

If you have an affiliate link within a product review, and the reader can see both the review and the disclosure like 'I get commissions for purchases made through links in this post - this is all you really need.