Which type of Google ads campaign is best for leads generation to Service related category. Search ad or Display(Image) ad or Video ad. If anyone have unique idea regarding this please share your idea with us
It depends on your goals, and the specifics of your market.
Search has high intent, very good for direct response. You should probably start here. Display reaches out to information sites well, sometimes a second layer, but if people aren't searching for your service (perhaps it's unique, or unknown), then this can be your primary attack. Video is difficult, the viewers are watching free content and often have low buying intent. If you target things tightly though, you can scale your reach very well here, including subject matter experts, and the video ads are more engaging (yet not not obnoxious) than Display or Search.
Do all 3, have goals, measure results on each differently, stick to your plan unless data demands you make changes.
Lead Gen on Google Ads can be very lucrative! Good luck to you!
Not sure what type of service you're referring to, I have a lot of "home services" clients and they get the best cost-per-lead results from search ads. I generally don't recommend display unless you've totally tapped out your other opportunities