How does this compare to NAPD Contract? Well, we usually consider the Corp gaining money to be better than the runner losing money, and this gains more on access than the runner would lose when they access NAPD. Plus it doesn't have the drawback of being harder to score when you get bad publicity, which is relevant now that Valencia Estevez: The Angel of Cayambe is around and also frees you up to play illicit ice in your deck like Grim. The main drawback of this card compared to NAPD is that you never have the situation where the runner accesses it but is unable to steal it. (Plus it can only be used in NBN).
What does NBN do best? Either fast advance astrotrain, or Scorched Earth. Both of those strategies need a lot of credits to work, and both of them are not too concerned if the runner manages to steal an early agenda (in fact, if you're playing Midseason Replacements, you actually want them to steal an agenda... and this card gives you just enough money to play that operation. Coincidence?) Here is an example of a possible turn: Pop-up Window, SanSan City Grid, Explode-a-palooza. If the runner decides to run that server, steal your agenda and trash your SanSan, you gain 6 credits and the runner loses 6 credits. That's like you Account Siphon them, except that you're the corp. If they don't run it, you can score the agenda next turn.
The flavor of this card is the icing on an already delicious cake. Same old action movie, still gonna make a ton of profit out of it.