Hi,
when someone clicks on the Interested icon in a market post, does that mean that all he wants to do is track that post, or is he expressing interest in purchasing the product and he expects the seller to contact him?
How does this work…please clarify.
Vivek
Ya. The purpose of the “Interested” link is to list the specific threads of FS or WTB, you are interested in, in the “Market Watch” segment which already lists your own Market threads (i.e. the threads you started yourself).
As you may have noticed that the number of posts in the Market section is relatively very high. So the whole idea of “Interested” or to be precise, linking the thread by clicking the “Interested” link into “Market Watch”, is that you never have to search for a thread of yours which you want to keep a tab on, or a specific product you want to keep eyes on.
To be specific, the idea is to give you the comfort of keeping all your Market buys and sells in one single place. Also, the “Market Watch” page gives you the power of closing or reopening a market thread you have started yourself.
I hope that must have clarified your doubts. 
It might be both. But it doesnt mean that the seller ‘has’ to contact you. Its better you also pm to the seller.