Start by identifying which metrics matter: you want high reach × high conversion × reasonable budget. In other words, you're looking for strong ROI channels — those that convert many people efficiently without being overfunded.

Let’s assess the channels:

• Email has a strong 2.5% conversion rate, moderate reach (30M), and a manageable 20% budget.
• Paid Search also performs well: 1.9% conversion on 40M people, with a 25% budget.
• Social Media has high reach (80M), but a low conversion rate (0.8%) — less efficient.
• TV and Events have lower reach and weaker conversion (TV at 0.3%, Events at 0.6%). You should eliminate these options before doing any calculations.

Now let’s pressure test:

• Email: 30M × 2.5% = 750K conversions
• Paid Search: 40M × 1.9% = 760K conversions
• Social Media: 80M × 0.8% = 640K conversions, but with higher spend and weaker conversion.

From this, Email and Paid Search deliver the most conversions at the best efficiency — and together only use 45% of the budget. As a further consideration, the client should consider shifting budget from other segments like Events and TV towards Email and Paid Search.