I attended an interesting TiE meeting for charter members which discussed angel investing, because TiE has now started a special interest group for angel investors. One of the topics for discussion was - How do you choose which entrepreneur to back? Seasoned investors spoke about the metrics they use to evaluate a founder, such as : has he been referred by someone they trust ? what's the total addressable market ( TAM) ? how passionate is he? what are his credentials? has he been able to put together a sterling team? Pretty standard stuff , which most of us are familiar with.