Pay per click advertising can increase traffic to your website, and also expand your knowledge of your market. If set up correctly, controlled and measured, it can generate revenue and healthy profits. On the other hand, when set up incorrectly, your paid search marketing efforts usually end up costing you money and may become a liability to your business.

It's not difficult to start a paid search marketing campaign. In fact, it only takes a few short minutes. But starting and running one are quite different. To begin a campaign, all you need to do is create an account, add a method of payment, and let traffic flow. To run a successful campaign, however, you need to research, plan and implement proper strategies to achieve better than average results.

Oftentimes a campaign is doomed before it even starts, because of common errors that could be avoided with proper planning and research. Below, I have put together a list of eight of the most common mistakes:

1. Using large, non targeted, broad keyword lists.

Large lists of non targeted keywords generally attract non targeted visitors. Rather than focusing on these massive lists (sometimes referred to as keyword dumps), you should focus on smaller, more targeted lists. In addition, refrain from using "broad match" keyword types, without any offsetting negative keywords. The use of alternative match options will likely yield less traffic, but that traffic should be more qualified.

2. Paying too much attention to your CTR and not enough to Conversion Rate.

CTR (or Click Through Rate) means nothing if that traffic does not produce actions (sales, in the case of ecommerce sites). Focusing on CTR only, as an indicator of paid search success, will only end up costing you money in the end (thus the pay per click concept). Instead, pay more attention to your paid search Conversion Rate to get a better idea of whether you are moving in the right direction or not.

3. Not looking at your Value per Visitor in relation to your Average CPC.

Your Value per Visitor represents the amount of revenue you earn for each visitor that arrives at your website through a paid search click. Your Avg. CPC (Average Cost per Click) is the amount you spend on average to get one visitor to your site. Comparing the two tells you whether you are making money or not. If your Avg. CPC is less than your Value per Visitor, then you are making money. The further the two numbers are apart, the more money you are making. It goes without saying that if your Avg. CPC is more than your Value per Visitor, then you are losing money.

4. Using only one Ad Group for multiple sets of non related keywords.

Setting up only one Ad Group and loading it with multiple sets of non related keywords does a number of bad things. It restricts your ability to more accurately target your visitors, based on ad copy. It can cause your quality score to suffer. It costs you more money and also can cost you ad position. I'll sum it up as follows: using one ad group will often result in non targeted traffic at a higher cost, with a lower ad position in the results. This is no way to succeed at paid search.

5. Using only one ad copy variation per ad group.

I see it often. Website owners running paid search and only using one ad to generate traffic. To be successful and find out what really converts, you should use at least two different variations of ad copy per ad group, and that's only a gauge. Three to four different ad variations is even better.

Running different ads against each other across one ad group helps you learn what triggers your market to act, and what triggers them to buy. It enables you to test what works and what doesn't so you can zero in on higher conversion rates.

6. Not turning off Content Network at the start of a campaign.

Until you know what you are doing, one of the first things you should do to save yourself some money is to turn off the Content Network option (on by default). Traffic from the content network typically converts at a much lower rate than traffic generated through the search network. There are ways to increase this content network conversion figure (combining placement targeting with proper landing pages is an example), but it takes a lot of time to get it right. The longer you leave the Content Network turned on, the more money you'll likely spend and the lower your paid search conversion rate will go.

7. Not setting a Daily Budget.

If you don't set a daily budget, you're opening yourself up to unexpected charges and possible wasted advertising dollars. The easiest way to set a budget is to come up with the amount you are willing to invest in advertising per month, and then take that amount divided by 30 or 31 (days in a month). Then allocate that daily advertising spent across the number of campaigns you have. This does not ensure the most visible campaign, but it will ensure you rarely exceed your budget.

8. Running all paid search traffic to a single landing page.

Driving all the traffic your paid search receives to a single landing page (i.e. the home page) is going to typically result in less than desirable conversion rates. The better method is to set the destination url at the individual keyword level, to allow more control over where traffic is routed.

This list should get you started on the right foot, and give you a better chance at success when starting your next paid search marketing campaign.

Eric Leuenberger is an ecommerce conversion expert and author of a leading Ecommerce Optimization blog (www.zencartoptimization.com). He coaches etailers, wholesalers, distributors and manufacturers to increase their website sales through online paid search advertising, targeted marketing strategies and website sales strategies. Contact him at 1-877-481-2323.