While inbound marketing is clearly on the ascent and has proved to be effective and a great value, outbound marketing remains a necessity.
In isolation, inbound marketing has limitations:
It can be challenging to target specific audiences with inbound marketing. Particularly in the beginning of inbound marketing campaigns.
Inbound has limitations in driving people to action. While it's best for the buyer to control the momentum of the sales process (consistent with the "pull" of inbound marketing), there will always be a need to "push" a prospect to take some action.
To extract the maximum value from marketing investments, companies need to combine inbound marketing with outbound marketing.