How do you determine the most effective channels for your campaigns?

I would start with historical data, if available. Based on past trends, you can identify your safe bets, as they have proven to be effective over time.

Suppose you are in more of an experimentation phase. In that case, I would focus on identifying where your customers and prospects trust and prefer to get their information. Consider testing these channels with low-budget investments to see if you can generate positive signals that you could then double down on.

I always like to go back to the point of understanding where your target audience likes to go for information. This approach is particularly helpful for being more prescriptive in channel selection.