Regional and city advertising are usually used by advertiser with an audience in a defined and constraint area. For example regional specific businesses like hotels, stores, restaurants and boutiques will find this ad targeting option very useful. This option does not only help to keep your quality score high but also keeps your costs low. The users that click on your ad are also more qualified.
It is important to note that regional and city ad targeting are not offered in every country. Some countries do not offer the infrastructure to allow Google to detect a user’s location. It is still possible to achieve a regional and city targeted ad campaign by making use of a national targeting campaign. This can be achieved by including the relevant cities and regions in your keyword list and ad text. Google AdWords will then display your ads for queries related to those cities and regions. You can also add the regions and cities that you do not want to target as negative keywords in your keyword list.