Rashbam draws out the meaning of the metaphor the Torah uses for gossiping.
“Do not circulate like a peddler (rachil)” (Leviticus 19:16). Someone who goes from city to city [hawking merchandise]. [The phrase means “do not be a gossip”; a gossip is referred to as a peddler because he goes around from one person to another to tell tales. (Translation Martin Lockshin)
Rashbam’s grandfather, Rashi, has a very different understanding of the metaphor intended by rachil.
I say that, since all those who instigate quarrels and speak evil talk go into their friends’ houses in order to spy out (l’ragel) what evil they can see there, or what evil they can hear, to tell in the market-place, they are called those who go about rachil, which is the same regila, “spying”. (Rashi translation from Chabad)
Rashi uses a similarly sounding word (which scholars do see as potentially linked in meaning) to suggest that a gossiper is like a spy.
Gossiping is like spying, because you try to gain access to information that reveals weaknesses, negative qualities, or anything else that should have remained private. Gossiping is like peddling because once you have the information, you go around trying to get people to listen, just as if you were selling something.
Now, I think the larger issue is not about the supplier (i.e. the gossiper), but about the demand (everyone who listens and seeks out juicy gossip). A peddler can only persist if there are buyers.
Which metaphor do you prefer for thinking about gossiping, the spy or the peddler?
For more about Rashbam, see my introduction.