I wouldn't bother with bought likes. They're usually hollow - easy to spot, and they do more harm than good when you're trying to build genuine credibility.
On LinkedIn especially, a handful of thoughtful comments from real people in your space will always outweigh a heap of hollow engagement. I'd pour that energy into warming up your network beforehand, asking a few trusted contacts for honest feedback, and making the launch post genuinely useful rather than just promotional.
Over on X, same principle applies. Real replies and shares from people who actually care about your niche beat vanity metrics any day. Fake engagement might give a little dopamine spike, but it can shatter trust if anyone notices. And trust is the one thing you can't buy.