Selection of keywords is very important part of creating PPC campaign.
Keywords selection should be started with revealing of the most obvious variants. It is using of website´s keywords. For example "window", "conditioners", "transportation", etc. These keywords not always turn out a profitable variant, as it is a high competition on them in 99% cases, but law enough conversion. Therefore it is better use them as a starting point for keywords selection.
The next easy way to find keywords is looking through websites of competitors. First look at meta-tags, headings and most often used words.
These keywords should be investigated, for example, with 7search.com Keyword Suggestion service for the purpose to define amount of the keywords searches and list expansion. As a result it should be turned out a big list of keywords with enumeration of searches amount. It is obligatory to add words with misprints (for example, “notebook”) or wrong spelling names and synonyms to this list.
For the purpose to increase effectiveness you should use negative keywords. (Negative keywords prevent your ad from appearing if search terms doesn´t unrelated to your website). For example, if your sell mobile phones and you have set “mobile phone” as a keyword, you can prevent demonstration of your ad when searches are made on “repair of mobile phones” by defining “repair” as a negative keyword.
There are classical ways of keywords selection. Besides there are also less widespread ways which will be considered at other articles.
PPC Search Engine Advertising Basics.
Basic knowlege about PPC. Keywords and Ad structure, bidding strategy and targeting.