The title implies to groups, I'm not sure which category you're in, I have spent time in both camps: WCM vendor and Digital Agency. Inextricably linked and yet, entirely different.

WCM Vendor

While working at Immediacy I'd often hear this type of conversation.

Commercial: Client X wants us to do the implementation, it's worth Y, let's get our PS team on it.

Delivery team: There's a UX component — don't have the skills in-house, there's an integration piece — don't have the skills or development environment. This project is way outside our comfort-zone.

The commercial team and client both rationalise: Vendor built the product, vendor knows best how to implement and deliver our project.

That's a bit like concluding the best concert pianist has to be someone called Steinway.

Digital Agency

Not all agencies make great pianists! Seriously though, a digital agency is a very different animal to a WCM vendor, the 2 parties should not be confused. When selecting your agency to deliver a WCM project, you'll want to be sure they have the technical depth; accredited developers with experience that stretches beyond one implementation would be a good place to start. Your chosen agency will also have UX and design skills and experienced project managers. They will have a number of disciplines onboard that a vendor does not pretend to understand. Ask a vendor to define what a planner does — it's like asking a northener where Windsor Castle is!

Conclusion

Adrian Newey would not drive his formula 1 racing car and expect to win.

Henry Engelhard Steinway, if he was alive, would not be found playing his beloved instrument in public — for money!

Doctors do not have the time or skill to run the NHS.

Agencies and vendors happily co-exist in the WCM eco-system. Happy providing they know and value their respective roles.

/discuss