Cookies

Cookies are small files saved in the browser by the website. In CPA, they track where the user came from and who should receive the conversion credit. When the user clicks on an affiliate link, a cookie is created with a unique affiliate identifier (subid, clickid, etc.). If the user performs the target action while the cookie is active, the system counts the lead.

Cookie lifetime in CPA

The lifetime of a cookie depends on the offer and tracking settings:

• 24 hours: for quick decisions, for example, in e-commerce;
• 7-30 days: the standard for most verticals;
• up to 90 days: for niches with a long deal cycle, such as finance or SaaS.

It is essential to consider that the longer the lifetime, the higher the chance of "catching" a conversion. But with repeated visits, priority often goes to the last source.

Cookies vs postback: which is more accurate?

Cookies are a less reliable method. They are stored in the user's browser and can be deleted, reset, or blocked by extensions. Postback (server callback) works directly between the affiliate program and the tracker. It transmits the conversion event without the browser and is very accurate. If accuracy and scale matter, use postback tracking. Ideally, combine both methods: use postback as the primary method, and cookies as a backup option.

How do browsers block cookies?

Modern browsers (Safari, Firefox, Chrome) are increasingly blocking third-party trackers, as those set not by the site itself but through third-party scripts. Safari applies ITP (Intelligent Tracking Prevention) and reduces the cookie lifetime to 24 hours. Firefox blocks third-party trackers by default, while Chrome is implementing Privacy Sandbox, using aggregated signals instead of cookies.

All these actions reduce the effectiveness of cookie tracking, which is why the market is gradually shifting toward server-to-server solutions and more efficient data handling.