As a kill skill, F0ll0wthr0ugh lasts for 7 seconds.
F0ll0wthr0ugh can produce very dramatic increases in speed, particularly if paired with a good Shadow Stalker class mod. This can aid Zer0 in closing distances very quickly. As such, it combines naturally with powerful, short-range attacks, including melee attacks, shotguns, and inaccurate SMGs or pistols.
Combined with Innervate and a good Shadow Stalker or a Legendary Ninja class mod, F0ll0wthr0ugh gives Zer0 a tremendous boost in movement speed if it is active during Decepti0n, allowing Zer0 to cover significant distance, which is increased even further by using Execute.
As with all Kill Skills, subsequent kills extend the duration on F0ll0wthr0ugh, potentially having it last through an entire fight.
The increased melee damage combines particularly well with Many Must Fall (amplifying repeated Execute slashes after the first, which gain less of a natural benefit from Decepti0n, and aiding in positioning for the next strike, possibly gaining more use from Backstab or Ambush as well) and to a lesser extent with C0unter Strike (both in getting the initial kill and in closing distance to subsequent targets during the latter skill's narrow window).