What metrics are crucial for SaaS PPC success?

For SaaS PPC success, crucial metrics include Conversion Rate (specifically for trial sign-ups, demo requests, or direct purchases), Cost Per Lead (CPL) or Cost Per Acquisition (CPA), and the eventual Customer Acquisition Cost (CAC) and Customer Lifetime Value (CLTV). Other important metrics are Click-Through Rate (CTR) for ad relevance, Quality Score for ad efficiency, and impressions and clicks for reach. Unlike general PPC, the focus is heavily on lead quality and the downstream conversion to a paying customer, rather than just traffic volume.