I had mistakenly activated the mobile ad option in my company's google ads account. We had about 5-10 calls a day coming from mobile ads, and 100% were accident

I had mistakenly activated the mobile ad option in my company's google ads account. We had about 5-10 calls a day coming from mobile ads, and 100% were accidental. In fact, we had to track down the source for all these calls for weeks, because it didn't make any sense to anyone (neither us or the callers). After that I carefully digged through all of our google ads activity. I finally deactivated absolutely all automatic placement and authorized only the main search page and a few selected sites, because none of the placements made any sense. Most of the clicks came from video pirating site and the likes. My impression now is that 80% of all web ads are slightly disguised scam, and completely useless unless you're selling stuff targeted to the most clueless, naive consumers (ringtones, phone games and the like).