With a list, you can take action on numerous accounts at once. That includes launching campaigns and creating/refreshing Snapshot Reports! To build a list, go to Partner Center > Businesses > Accounts, use the filter to narrow down your results, and then click Add [# of Accounts] to List.
Then, create a new list or add the accounts to an existing list.
You can take action on this list via Partner Center > Businesses > Accounts > Lists.