This is a hard problem to solve, and it's only become worse now with Facebook's direct buying platforms. Kenshoo, Omniture, Blinq, and others are all now offering FB buying functionality. But whose is better? It's hard to tell because you must answer very separate questions before you can begin to make decisions of trade-off. And let's not avoid that part -- you will have to make trade-offs between specialization and integration, based on your organization's current capabilities and future capabilities that you desire to expand into.
The first component is to address core functionality and make sure the tool has the ability to meet your needs. This is true whether you are looking for a PPC or Facebook platform. Once you do this, you should have a core set of contenders. Test them all. Seriously, test-drive each of them. You must commit the resources and time to ensure you understand who the companies are and how the tools perform under stress.
You should measure success by evaluating each on a variety of metrics, but all of them will fall under two general categories. The first is operational efficiency gains; the second, campaign performance gains. Granularly evaluating each of the tools against these will help you isolate one or 2 two leading partners. From there you have to know how nice these tools play in the sandbox. If you expect to see a holistic and even a cross-media view of digital, you must ensure your tools work together fairly easily.
The best tool here may not be the best for you. If you can't see SEM in conjunction with display and/or site analytics, then your attribution model will suck. If the pricing isn't right, you can't come to the best commercial arrangement, or maybe the learning curve for having multiple tools in place is too steep, then the value you extract from the tool also sucks. Any of these can force you to select down on functionality in an effort to select up on capabilities and insight.
All the vendors/technologies/platforms/tools [pick your label] have different ways of delivering integration and specialization. You need to find one that will work within your organization's structure and priorities (for example, site analytics first and all else secondary -- or SEM first and all else secondary, or even integration first, etc). Part of the trade-offs may be that you need to wait as your partner rolls out expanded or tailored functionality. If this is the case, you will need to get a feel for how flexible the technology platform is, and how well the company delivers releases. Talk to their customers. Look at past roadmaps.
The goal of all this is to find right partner for you - maybe not the fanciest tool or the newest tool or even the one with the most robust functionality, but one to drive results and improve your overall efforts.
Coming up at the next Search Insider Summit in December, I will be moderating a panel on this very topic, and I hope the attendees will walk away with a better understanding of how to answer these questions for themselves. Companies represented on the panel will be Marin, Adobe, MediaMind, and eFrontier. Please come armed and ready for a no-holds-barred shoot-out between some of the industry's best.
See you all in Utah for another amazing SIS. Here's to the best search conference in ski country!!