You might be interested to know that I have been on both sides of this conversation. I have managed in-house marketing for a large ecommerce company and also ran strategy at a digital agency for some of the biggest businesses in the world.
The problem with most online marketing campaigns run by digital agencies consist of two real reasons.
#1 - Most agencies don't do their homework. Online marketing campaigns require lots of work upfront. Smart campaigns, customized to your individual business bring the best results -- but most agencies don't really think about your business. Agencies too often only think about how to get you to sign the contract.
They don't know your products or understand your customers.
Also, if you start a campaign without clear objectives, tools for measuring, and back-up plans for when things don't go as planned you will find yourself in trouble.
#2 - The second factor that plagues online marketing campaigns but is easily fixed (especially if you already are doing #1) is optimization.
You start the campaign small to save money and effort. You find what works. Then once you know what is working you stop doing what isn't working and spend your efforts at ramping up what is working.
Then you continue to test and refine your marketing campaign. Continuous optimization creates significant cost savings which is a major factor to ROI.
If you can't reduce costs it requires you to make a significant amount of new revenue to make up for over spending.
These two factors drive a lot of the issues businesses have with agency led digital marketing. If you need help at getting the most from a marketing agency, or just need to know what you can do to drive strong, measurable ROI let me know.
A few minutes can save you a lot of headaches. I'm just a call away.