I think recommending products and services that have impressed in some way is a natural part of Twitter conversations.

Spam in Twitter is tweets such as that which suddenly appeared under a friend’s name: “Made an extra $xx today by using tips from [url link].” Someone hijacked the account to tweet spam.

In this case, they misjudged both the account holder and their correspondents, who immediately questioned the tweet, and the spam scam was spotted.

I wonder how many aren’t so easily spotted, better disguised as personal recommendations.