Hi, I am totally new to Adwords, but I know what it is about through some researches and I am going to set up an Adwords account. However, I am thinking about the risk of competitors keep clicking on my ad, costing me money with no business coming in. Is there any mechanism in the account to stop the same person clicking on the ad for more than a certain times?
Google have systems to detect click-fraud in place. In the scenario you describe, you wouldn't be charged for the clicks. You can read more on how Google describe their click-fraud detection methods here - https://adwords.google.com/support/aw/bin/answer.py?answer=6114
Competitors will likely click on your ad to check you out once they see your ad. But it's not something to much worry about. It's not as if half your clicks will come from them plus Google has good click fraud detection. Cost of doing business if you get a handful of clicks each month out of hundreds or thousands. I have my own code of conduct as a PPC advertiser that we should all follow: 1) use google.com/adpreview to check out the competition. On that site, impressions are not counted. I'm not one to constantly check my own ads, those of competitors or natural rankings. But I know that some are obsessed and check daily, sometimes many times daily so the impressions can add up and affect everyone. 2) never click on competitors ads. Another reason to use the preview site since you can't click on the ads. By clicking, you are only helping them with better QS anyway (and you with a poorer one) but also costing them money so it's a double-edge sword. You don't want non-converting clicks so don't do it to others. It would be nice if advertisers had a gentlemen's agreement and all advertisers follow these two simple rules.
We have not seen a major problem with this, the bigger issue is having quality keywords and ads that match your content, or google will be taking your money by charging top dollar for your clicks..