Aren't they scamming their advertisers too? Because if you click the back button a bunch of times it's gonna reload a bunch of them on every click. At least if your internet is fast enough.
Impressions are usually deduped, meaning multiple impressions from the same user during the same session are just counted as one. The big ad networks are extremely careful to avoid miscounting of any sort and will generally err on the side of undercounting rather than overcounting (since telling advertisers they got more impressions or clicks than reported is way better than telling them the numbers were accidentally inflated). Of course, there's the occasional bug, but it mostly works as expected.
Does it also cover reloading with different ads? (such that it would count impressions for different advertisers)
Usually the ad needs to be in your viewport for at least a few seconds to count as an impression. If you were just going back quickly, or quickly refreshing the page, it won't count. If you go back or refresh, see a different ad, wait a bit, then refresh again, I think it'd count.
For skippable ads on YouTube, the advertiser only pays if you watch past the point where you can skip it. If I remember correctly, you have to watch at least 30 seconds of the video (or the full video if it's less than 30 seconds) for it to count as a view.
I just realized you meant data deduplication instead of "not duped by you bitches anymore"
Aren't they scamming their advertisers too? Because if you click the back button a bunch of times it's gonna reload a bunch of them on every click. At least if your internet is fast enough.
Impressions are usually deduped, meaning multiple impressions from the same user during the same session are just counted as one. The big ad networks are extremely careful to avoid miscounting of any sort and will generally err on the side of undercounting rather than overcounting (since telling advertisers they got more impressions or clicks than reported is way better than telling them the numbers were accidentally inflated). Of course, there's the occasional bug, but it mostly works as expected.
Does it also cover reloading with different ads? (such that it would count impressions for different advertisers)
Usually the ad needs to be in your viewport for at least a few seconds to count as an impression. If you were just going back quickly, or quickly refreshing the page, it won't count. If you go back or refresh, see a different ad, wait a bit, then refresh again, I think it'd count.
For skippable ads on YouTube, the advertiser only pays if you watch past the point where you can skip it. If I remember correctly, you have to watch at least 30 seconds of the video (or the full video if it's less than 30 seconds) for it to count as a view.
I just realized you meant data deduplication instead of "not duped by you bitches anymore"
lol yeah I should have been clearer