Just yesterday I lamented the link bait potential of top 10 lists. Well, today, I'm borrowing from two other SEMers to compile my own list of 10 PPC mistakes. Both Jennifer Laycock at Search Engine Guide and Amber at PPC Hero recently touched upon 5 PPC mistakes that they believe were both common but easily avoided. So I've summed them up for you here.

First, over at Search Engine Guide, Jennifer explores 5 common paid search mistakes by (1) identifying what the mistake is, (2) explaining why it's detrimental, and (3) suggesting a solution. They are enumerated below in bold, with my own synopsis following in a normal font-weight.

1. Ego Bidding - This is basically a case of trying to rank first for very general phrases/keywords, which is expensive because they tend to be competitive and, because they're general, convert poorly.
2. One Ad, Many Keywords - This is simply bidding on many keywords with only one add, and the problem include untargeted traffic, higher CPCs, and poor visibility.
3. Focusing on Budget Instead of ROI - Here we have the PPC version of not being able to see the forest from the trees. Basically, PPC makes it possible to track clicks, obtain metrics, and actually generate revenues directly from ads, so fixed budgets don't really work for PPC campaigns.
4. Mistake #4 - Sending All Traffic to One Page - Not only does this cost you valuable metrics on what ads/keywords are converting, but they might cost you credibility with the adsever which will harm the visibility of your ads.
5. Not Separating Content from Search - In a nutshell, user intent is differs according to whether they're conducting searches or just surfing sites on the adservers publishers' network, and PPC advertisers need to keep this in mind when determining the distribution of their ads.

Now I cannot stress enough just how much more detail Jennifer goes into. So if running a PPC campaign is part of your mandate, you should definitely check out the original post because it offers solutions to go along with its diagnoses.

When it comes to PPC campaigns, however, five pointers are scarcely enough. Fortunately, Amber elaborated on Jennifer's with 5 additional PPC mistakes of her own. Again, her points are listed below in bold, with my own synopsis following in a normal font-weight.

1. Not Spending Enough Time on Your Ad Text - Indeed, ad copy can both attract users, as well as pre-qualify clicks to improve conversions by preventing superfluous click-throughs.
2. Not having a Relevant Landing Page - This point overlaps somewhat with Jennifer's #4 point above, but focuses more on the fact that the top-tier search engine will rate the quality of your ads based on how relevant they believe the landing pages for those ads are.
3. Not Checking Up on Your Competition - This is simply a case of knowing what the competition is up to so that stand out from them by either (1) surpassing them, or (2) distinguishing yourself from them.
4. Not Using Negative Keywords - Because phrases are composed of individual words, you can end up paying for a lot of clicks that don't convert if you bid on a phrase whose composite keywords are not relevant to what you are advertising. For this reason, you need to anticipate what keywords (individual or combinations) you don't want to bid on, and indicate that these are you negative keywords..
5. Only Using General Keywords and No Long Tail Keywords - This point is somewhat of an extension of Jennifer's #1 point above: namely general keywords are broad and, therefore, competitive, so you might want to think more in terms of what you're actually advertising. Indeed, the long-tail is prudent in the same way that many general keywords should be your negative keywords.

Although her original post isn't as structured as Jennifer's, Amber also goes into more detail. Consequently, you might want to check that our for yourself, as well.