I cant asume future impact of this service at this moment.But here is about it direct from google-- Click-to-call ads turn clicks into phone calls. New click-to-call ads can put customers on the phone with you the moment they see your Google ad. Web users click your ad and enter their phone number. We call them instantly and put them on the line with your business or call center. You pay only when a call is made, at the price you set -- no long distance or other phone charges. click-to-call ads participate in the same AdWords auction as text ads, and receive the same ad discounting benefits. Ads are ranked according to price and quality score, as always, so you may not see your click-to-call ads serve for every query. Here's how to get started: 1. The AdWords wizard will help you create a separate click-to-call campaign and ads. Helpful AdWords features like location targeting and ad scheduling can be used with click-to-call campaigns. 2. The wizard will ask for your phone number and company name, which will appear in place of the display URL seen in text ads. Direct phone numbers are preferred, since they give interested callers the best user experience. However, call center numbers are accepted. 3. Add your unique keywords and creative text. Write ads different from the ones running in your keyword campaign. Include a strong call to action that encourages users to contact you right now. 4. You'll probably need to bid more for a call than you would for a click to get a comparable ranking. If your ads are not being ranked as you would like, try making your keywords more precise, or raise your bid. 5. Your ad will run only on Google. It can go live almost immediately. 6. Check your Campaign Summary page for activity reports on your click-to-call ads.
I havent yet tested it in our account , though it is enabled in our account. But our adwords rep said it works well for india .