There are so many challenges, but which is the biggest depends on the specific players and where they are in their content marketing evolution. The three biggest challenge areas (and the ones I assess at the beginning of any content marketing consultation or project( are:

1. Strategy - Depending on the client, the challenge may be convincing them of the need for a strategy or coming up with one all the stakeholders can agree on. Strategy development can also be a challenge because it often involves a lot of discovery around branding. When you start digging into who you're writing for and what they need and how you're meeting that need (or not), it tends to uncover all kinds of insights about messaging and positioning and so on. That's all GREAT, but the client has to be prepared for that (and the consultant needs to know to factor that kind of exploration/discovery into her project budget.) It's kind of like therapy - you start with one "simple" question and wind up knee-deep in something totally different. ;)

2. Resources/Content Development: This is where most people expect to be challenged. The problem can be lack of resources, lack of trained resources, or too heavy a drain on the marketing budget (for outsourced content). The best approach to this challenge is a sane one. Be realistic. There are few things that will kill future content marketing initiatives as giving someone a reason to say "I told you so" when your first attempt falls flat. Explore alternate content creation and curation ideas - different mediums (video, audio, etc), repurpose pillar content into multiple pcs, and come up with a manageable content curation plan that can augment the development of original content.

3. Continuity/Perseverance - Once you've got past the rush of strategy and initial content creation, you've got to step it up so that you can keep it up. Content marketing is not a sprinter's game - it's an ultra-marathon. The team needs to be prepared to be in it for the long haul. Think about scheduling check-ins, intermittent brainstorming sessions to freshen things up, and other ways to keep the inspiration going.

4. Measurement - Measurement is usually considered to be at the end of the content marketing cycle, but it really needs to be thought of at the very beginning as well: what are you measuring, how are you measuring, when will you measure, AND what actions will you take based on the data you get? It's also important to measure on an on-going basis. Most content campaigns are on-going, so think about the measurement on a continuum instead of a finite line. Pay attention to "little" measurements and feedback - they often uncover opportunities to optimize or expand on a certain piece of content.

Are there big challenges to content marketing? Yes. Is the effort it takes to overcome these challenges worth it? YES.