Those of you who do not know this and wonder as to how Google became such a big name in the social media industry, their business model is really multifaceted.

A major share of Google's revenues constitute the earnings from its AdWords feature. In fact, it is Google's main advertising product earning a whopping $42.5 billion (2012 figures). The Adwords feature works on the CPC or cost-per-click advertising. This is nothing but the cost incurred by the host website to get their advertisement clicked on by visitors. How this happens is specifically through certain important keywords that are specific to the target market which are displayed on websites or listed on search engines according to their relevancy.

In 2004, Google opened AdWords feature to advertisers for a bid for key search terms. Despite being coming under the scanner for various trademark infrigements, Google has not abandoned this auction-based marketing model precisely because a large part of revenues come from this avenue.

So what are the most popular and most pricey keyword categories that advertisers are fighting out to grab. The real competition is to seek the top ad spot in the.

Wordstream, a reputed eCommerce firm just brought out a infographic last year after an intensive research, showing what are the most enterprising revenue categories that earns Google it's maximum share of revenue.

Here are the top 20 keyword categories that fetched the highest costs per click. Check out the infographic just below this list.

1. Insurance – $54.91 per click

2. Loans – $44.28 per click

3. Mortgage – $47.12 per click

4. Attorney – $47.07 per click

5. Credit – $36.06 per click

6. Lawyer – $42.51 per click

7. Donate – $42.02 per click

8. Degree – $40.61 per click

9. Hosting – $31.91 per click

10. Claim – $45.51 per click

11. Conference Call – $42.05 per click

12. Trading – $33.19 per click

13. Software – $35.29 per click

14. Recovery – $42.03 per click

15. Transfer – $29.86 per click

16. Gas/Electricity – $54.62 per click

17. Classes – $35.04 per click

18. Rehab – $33.59 per click

19. Treatment – $37.18 per click

20. Cord Blood – $27.80 per click


For more interesting infographics and data metrics, stay tuned to E-junkie.