Dear Hulbert Lee,

Thanks for you detailed reply, you have clear all points in a short way. Can you please add more about cpc? Current keyword has 0.27$ cpc. This is good or go through for more cpc?

The real question to ask yourself with CPC is this:
By knowing your numbers (how much you are likely to actually earn (or are earning) per click based on conversions on your website - EPC), you can compare that to CPC. If EPC is higher than CPC and you are sure about your earnings, then you are on track to make a profit.

If your numbers are not solid, test first before committing. Also, consider the opportunity cost of your keyword. You can't build pages and sites for every keyword under the sun. You don't have time. You want to leverage the BEST keywords that have the chance to earn you the most for every click.

A little extra time upfront with keyword selection pays off. Rather than broad or exact match, if you are looking at long-tail terms, phrase match is pretty helpful.

Nice information thanks