The advantage of using Project Junebug, over other ambushes such as Cerebral Overwriter and even Snare!, is the fact that it takes a solitary credit to fire it's ability. For the same amount of credits it takes to use Snare!, Project Junebug will cause double the net damage, enough to flatline a fully gripped runner. In metas seeing heavy Account Siphon and/or Vamp usage, and where the Runner won't run on remotes until the Corp has no credits, there nothing more frustrating the carefully laying out several traps only to not have the credits to use them. However, install Project Junebug behind a Pop-up Window and it doesn't matter that the Runner just Vamped your credits away. It is this low cost to potentially high damage that helps makes Project Junebug as dangerous as it is.