LOL, you're not selling a B2B SaaS with $500 a month on Meta. I've managed dozens of SaaS accounts from early-stage through Series B, and the maths just doesn't work at that level. Let me explain why.
At a conservative $50-80 cost per lead for B2B SaaS (depends on ICP, but if you're targeting decision-makers in startups, that's realistic), your $500 budget gets you maybe 6-10 leads. That's not enough volume to let Meta's algorithm learn conversion behaviour properly. The pixel will spend half the month still in learning limited status, meaning your CPA will be volatile and you'll waste budget on irrelevant clicks while the system figures out who actually converts.
Even at $500/day you'll need a solid attribution setup-UTM parameters, HubSpot tracking, maybe a server-side event for offline conversions-because Meta's native attribution tends to overcredit the last click and ignore the nurture sequence that actually closed the deal. For a proper testing phase I'd start at $100/day minimum, and even that's tight for a SaaS where the sales cycle spans weeks.
Also, check your offer: if the CTA is "book a demo" rather than a lower-friction asset (case study, free audit), your cost per conversion will spike. If you want to DM the product and ICP I can give you a benchmark on what realistic CPAs look like.
