Discussing about adwords is interested in for everybody. By Adwords someone got huge traffic and last you got sales. But, it is difficult to connect between landing page n, adwords and affiliate ( sales )
Agree with @Dating Port that you'll want to try a variety of sets of ads and keywords--this is the best way to figure out what works for you. Set up a few different campaigns or ad groups, and play around with different ad copy, different landing pages, and different sets of keywords (specific to a particular page vs. describes your whole site overall, 2-word phrases vs. 3-word or 4-word phrases, etc.). With our own clients, even then we often see that it takes up to 3 months for campaigns to ramp up and perform at their best. Then, constantly check in and tune things--for example, cut keywords that aren't performing well, adjust bids so that you're placing competitively in rankings for keywords that are performing well. It's a lot of work, I know--expect to put in a lot of time if you want to see good results, or even to hire someone specifically to take care of it. Disclaimer: I work for a company that specializes in automating online marketing for small businesses. Happy to tell more if you're interested, let me know. Otherwise, hope the advice is helpful.
Very appreciate all of your advise. It is a pity that i have to change my google adwords plan since the website need to be changed, and it is also quite strange that i can't open the google analytics recently.