Bot traffic is traffic generated by bots, so non-humans. Mostly, bots traffic is considered harmful and risky. They can either attack the site for data scraping and DDoS attacks (disruption of traffic) or are used to shuffle website statistics.
For affiliate marketers, it can be harmful since it can show traffic presumably generated by an affiliate. You have to pay for that traffic since you think that those are real users interested in your service or product. In fact, you pay for nothing.
Much modern software (and tracking software as well) can identify bots. However, if you have no access to this type of software, you can identify bot traffic by:
Suspiciously high bounce rate: If there are too many visitors who stay no more than a second on the website and almost none of them go see other pages, they are likely bots.
Too high or too low session durations: Session duration for every page is quite steady: almost all users need the same amount of time to review the page. If the number went too high or too low, it may mean that the page is skimmed by bots.
Weird conversions: Bots do not only visit the websites, they can even convert! If you see too many forms filled out by people with weird email addresses, names, and numbers, those are probably bots.
Yet, it is better to use software to react to bot traffic earlier and provide real proofs to an affiliate.
