The verdict
Start with Google Analytics, or a lighter alternative. You need to know which channels and pages work before you chase individual companies, and it costs nothing. If you run Google Ads and Search Console, the integration is the reason to pick it over anything else.
Add Leadinfo when you have a B2B site with steady traffic and a sales process that can follow up within hours. It pays back when someone acts on the alerts. It will not help a consumer site, and it does not follow a visitor into your sales process on its own, so connect it to your CRM. If your traffic is low or nobody will follow up, skip it and spend the effort elsewhere.