Typically, when a player is a "buy" or a "sell" in 15 Transactions, it's based on performance. If a wide receiver is seeing lots of volume and generating a ton of yards, but he's barely scored, then you might expect him to be a buy candidate. When the opposite is true, he's a sell.
Anyone who's read this column over the last five or so years -- however long yours truly's been writing it -- knows how things work.
Sometimes, though -- sometimes the recommended transactions are based off of the vibe of the fantasy football market.