How it works
A regular network sends each click to the MMP through a tracking link. A SAN does not share click-level data. Instead, when your app is opened for the first time, the MMP asks the network's API whether it recognises that install, and the network answers with a claim and campaign details if one of its ads was involved. The network applies its own attribution windows. Because several SANs can claim the same install, the MMP compares the claims with any other engagements it holds and credits the install once, by last touch.
Why it matters for an app team
For most apps the largest budgets sit with SANs, so the quality of these integrations decides how much of your spend you can measure. The MMP is the only place where competing claims are deduplicated.
In practice
Example with made-up numbers: in one week two SANs each claim 600 installs. The MMP finds that 150 installs were claimed by both, credits each of them to the later engagement, and reports 1,050 attributed installs rather than 1,200.
Common confusion
A SAN's dashboard will rarely match the MMP's. The network counts every install it claims, may use a different window and may assign the install to the day of the click rather than the day of the install. On iOS, installs from users who have not allowed tracking are generally measured through SKAdNetwork instead.