Something to do with social proof? All these people who suddenly want to be your "friend" affecting your subconscious willingness to do a deal with them?
Evangelical churches often do the love-bombing thing too.
If somebody who I don't know would suddenly eagerly want be my friend, first thing I'd do is to check if my wallet is still where it should be. Next thing I'd consider how rude I'd have to be to get rid of this wacko. I think "I want to sell you a car for the best price that you can pay while also making a little profit" would work much better on me.
Evangelical churches often do the love-bombing thing too.