Comapring apples and oranges.<p>Facebook ad clicks are not the same thing as advertised website&#x27;s uniques&#x2F;visitors&#x2F;hits&#x2F;sessions&#x2F;whatever. Especially if the latter is using external tracking that uses JS and tends to be blocked&#x2F;opt-out by some.<p>Facebook clicks are really &#x27;clicks&#x27;, not &#x27;unique people clicking&#x27;, they are also not &#x27;successfully redirected after click&#x27;, maybe not even &#x27;click successfully finished and not reverted by aborting&#x27;. It just means someone clicked or tapped on the thing used to advertise.<p>So yes, you get what you pay for, and in the case of Facebook it&#x27;s their definition of a &#x27;click&#x27; you are paying for.<p>By the way: 
You get pretty close to their numbers when using a redirect script that loads in a few ms and just writes &#x27;hits&#x27; to a database and then again redirects to you to your normal target website. Not 100%, but much better than using GA or any other external tracking on the target website.