Be wary of spam/junk leads if using Google Ads 'lead form' extension (not hugely common from what I find, but do see service-based and B2B businesses using the extension from time to time).
I'll post a more detailed breakdown once I've completed it, but long story short for an account I've recently reviewed literally 100% of the leads through the lead form (which, of course, Google reports as conversions) were "junk".
If you looked at the campaign in question purely from a headline performance figure perspective, based on what a conversion is worth to this business it would look very profitable indeed.
But scratch beneath the surface and another story emerges.
Most bizarrely, a number of the "leads" were real people (based on communication with them) who had zero recollection of ever putting their personal contact information into the form, who had never heard of the client's brand and product, and who would never be in a position to purchase anyway.
Stay tuned, as I'll post a more detailed breakdown ASAP.