Challenges in Cross-Market Lookalike Campaigns for UK Expansion

I'm working with a client who is expanding from their home country into the UK market. While I have comprehensive TAM data for the UK, I need to execute a lookalike campaign that identifies which companies in my current database most closely resemble successful companies from the client's original market. My current challenge is that available online resources primarily address lookalike modeling for scenarios with no existing data, or they focus on individual attribute matching rather than holistic company profiling for cross-market expansion.