US Patent 10929870 Advertisement impression verification using blockchain

Advertising impressions are collected and a block in a block chain is created for each impression or a set of impressions. Each block includes a hash of a preceding block in the block chain. The block chain may be traversed to analyze advertising impressions and determine their effectiveness. Advertising content may include embedded code that invokes transmission of a notification to a server. The server creates a block in response to the notification that includes data such as the advertising content (or a reference to it), attributes of a target consumer, information regarding an advertising campaign, and/or other data describing the advertising impression.