There was a good blog post outlining 13 myths about PPC. I have one or two to add to the list, but here are the top ones from that blog;

13 Myths of Pay Per Click

1) You need to be number 1 - Leave your ego at the login, you do not have to rank number 1 for the campaign to work or to get volume. Concentrate and optimise on conversion and ROI

Agree with that one 100%. You do not need to be number 1 for every search phrase.

3) The content network is all bad - Actually no. There are a lot of scare stories out there but in fact the content network can perform very well in some markets and for certain businesses. Set up the content network seperate to search, test and evaluate. Consider placement targetting on Google and remember site exlusion. Yes, even domain parking ads can work.

The content network is not worth the risk in my opinion. I’m not about to finance click fraud or trust everyone who has adsense on their site to only have legitimate clickthrus.

9) PPC is only short-term until organic rankings arrive - Pay per click can integrate with your SEO campaign. Test and measure individual and aggregate campaign data - If the PPC campaign delivers the right ROI then why stop?

Again, great advice here. Both organic results and PPC are necessary to your marketing plan.

11) Optimisation is campaign only, not the site - Don’t expect miracles from a campaign if you will not consider landing page and site improvements. That simple.

No truer words could be spoken. Don’t blame the traffic if your website is not able to convert the traffic into sales.

13) Adwords / Yahoo! / adCenter hates me - Maybe, but before complaning and going completely mad, make sure you read the help centre. I mean r-e-a-l-l-y read it.

Here are a couple I’d like to add.

1. Running your own PPC campaign is easy. Anyone can do it. I’m sorry. it’s just not true no matter what google, yahoo and msn adcenter tell you. I can’t count the number of people who have come to us after wasting thousands of dollars following the advice they get from google, yahoo, and msn adcenter. They want you to spend more money. That’s like taking the advice of the car salesman on which car to buy and how much you should pay for your new car.

2. Hiring a professional is too expensive. Not if you hire someone who is reasonable. Many SEO and SEM people are looking for only those customers with a huge budget and don’t want to do ppc for small businesses. So don’t be discouraged if one of them quotes you a huge price. Go somewhere else.

3. You can’t do well with ppc unless you spend more than $1000 per month. I see this written on many seo blogs and in forums. It isn’t true. I’ve run ppc ad campaigns that were $300 per month that produced $10,000 in monthly sales. So I know this is a myth. Don’t believe otherwise.