how to detect if a group buy is a scam?

[withnail]

I am sure my question has been asked millions of times before, but since I am a newbie I am entitled to newbie questions.

There is this group buy that looks very attractive, I am sure many of you will recognize it, three KNC neptune preorders (so far), each of which is divided into 32 shares, and each share costs .6bt. So the host will make a moderate profit from this. Now what I don't understand is that these machines are to arrive early next year then then the host will make much more money simply by keeping the machines to himself. You know where I am driving at: why does he do this? Altruism is a noble thing and it is important to share in this community, yada yada, I don't buy this. If he uses escrow then I will not be asking the question, but he is not.

Thrill me with your acumen on this one.   

[machinationus]

You just answered your own question, without escrow it's not safe. I've been scammed a few time but not for large amounts.
Even if you know the person they can and will scam, trust no-one.

[datbox]

I am new like you. I am also looking for a reliable group buy. I just look for those with track record and go through the pages. Those who have conducted few batches of group buy tends to be more trustworthy. Nevertheless, there is also risk involved. So do your own calculation and prepare for the worst.