If he's an approachable person, who doesn't try to lord it over you due to his ownership / position in the company, then I'd recommend taking a direct approach

If he's an approachable person, who doesn't try to lord it over you due to his ownership / position in the company, then I'd recommend taking a direct approach and meeting with him, data in hand, to prove your POV. Specifically, get the costs and benefits to do a simple ROI analysis. If you're in tech, you should be able to parse the logs to figure out how much traffic / revenue / other stuff you've gotten from your costs. Find or discover some (reasonable) social media metrics that you can use to break through the opacity of their "social media" benefits. Take all this to the CEO. Lay it out in front of him. Suggest that the investment is now a sunk cost -- he may just be protecting his ego at this point, so approach gently -- and that you think repurposing some of that money to facebook ads / etc. would result in X% better numbers. But that at your current budget ($20 / day), you can't bring him well-supported conclusions. Tell him that you need $Y to actually run the experiment, and that you can find that money by taking some from your SaaS cost. After a month or two, or whenever you have sufficient data, meet with your founder again with your data that supports your conclusions (if it doesn't fit, also realize that you may be wrong in this instance). If he doesn't seriously consider what you've brought him, then make a note that your CEO is somewhat clueless, ego driven, and stubborn. If your CEO is unable to see through snake oil salesmen, your company is in trouble.