How to measure marketing success?

Marketing metrics are important for assessing the performance of your campaigns, because without the appropriate measuring you're simply in the dark. I'll give you an example - imagine a local bakery owner promoting their new sourdough bread through social media ads. Without an idea on relevant metrics, it's challenging to measure the impact of these ads. Are more people visiting the bakery? Has the sourdough sale increased? Does anyone even care? Metrics provide answers to these vital questions.

A fundamental metric is Return on Investment (ROI), which evaluates the money earned against the money spent on marketing efforts. For instance, if you invest $100 on ads and make an additional $200 in sales, that's a positive ROI, you've done well. It clearly shows whether your marketing investment is paying off.

Engagement rate is another important metric, especially in the digital world. It measures how and if people interact with your online content. A higher engagement rate on the bakery’s social media posts indicates a good level of interest and interaction, which could translate to more customers. It doesn't always translate directly, but it can show you a tendency. 

Marketing isn't about guessing what will work anymore. It's about understanding and analysing the metrics, so you can make informed decisions, tweak campaigns for better outcomes, and track your marketing goals more efficiently. For a simpler life, various analytics tools and marketing dashboards are available so the process doesn't seem like such a maze. Start with Google Analytics for instance - it'll help you understand what's going on in your webpage. Then move on to social media tools like HootSuite or Sprout Social and if you're feeling particularly visual, look into Tableau for pretty graphs of your marketing successes. The world is your oyster!