I think marketing works but there's a tendency in most jobs for the work to move from doing the job to justifying the job. You hire someone to market your prod

I think marketing works but there's a tendency in most jobs for the work to move from doing the job to justifying the job. You hire someone to market your product, at first, they market your product. After ten years, they're spending half their time marketing the product and half the time justifying to you that the marketing works. It doesn't matter if they are good or bad at marketing--it only matters how well they can justify the rates that they charge their clients. If other marketing firms have bad data, you have to get data that's just as bad to compete. I personally think the only way out of it is to bring it in-house. You can try to formulate what you want from marketing in terms of impressions, CTR, etc., but these are all metrics and if you rely on metrics there are perverse incentives to game the metrics. This happens in every job, it's just that your marketing department has to spend a lot of money, so they are going to spend a proportional amount of time justifying why they spend that money, and it means that the marketing department wants to work with firms that provide them with the metrics that the department needs to justify marketing spend to the rest of the company.