Ads in a paper are generally brief, as they are charged for by the line or word, and are one newspaper column broad.
Publications printing news or other details often have areas of categorized ads; there are also publications which contain just ads. The advertisements are grouped into categories or classes such as "for sale-- telephones", "desired-- cooking area appliances", and "services-- plumbing", thus the term "categorized". Categorized advertisements generally fall into two types: individuals advertising sales of their personal products, and ads by regional organisations. Some businesses use classified ads to hire new employees.
One problem with newspaper classified advertising is that it does not allow images, even though display ads, which do allow images, can be found in the classified section.
Over the last few years the term "categorized marketing" or "categorized advertisements" has expanded from merely the sense of print advertisements in periodicals to include similar types of marketing on computer system services, radio, and even tv, especially cable tv but occasionally broadcast television as well, with the latter occurring normally really early in the morning hours.
Like a lot of types of printed media, the classified advertisement has found its method to the Web, as newspapers have taken their categorized advertisements online and new groups have found the benefits of classified marketing.
Internet classified advertisements do not usually use per-line rates designs, so they tend to be longer. They are also searchable, unlike printed product, tend to be local,  and might promote a greater sense of seriousness as a result of their day-to-day structure and larger scope for audiences. Because of their self-regulatory nature and low expense structures, some companies offer complimentary classifieds globally. Other business focus primarily on their local home town region, while others blanket city areas by utilizing postal codes. Craigslist.org was among the first online categorized sites, and has actually grown to become the biggest classified source, bringing in over 14 million distinct visitors a month according to Comscore Media Metrix.  A growing number of websites and companies have actually begun to offer specialized classified markets online, catering to specific niche market items and services, such include boats, pianos, family pets, and adult services, amongst others. In most cases, these specialized services provide much better and more targeted search abilities than general online search engine or basic classified services can provide.
A variety of online services called aggregators crawl and aggregate classifieds from sources such as blogs and RSS feeds, instead of counting on manually submitted listings.
In addition, other companies offer online marketing services and tools to help members in designing online ads utilizing expert ad templates and after that instantly distributing the finished ads to the numerous online advertisement directories as part of their service. In this sense these companies serve as both an application service supplier and a material delivery platform. Social classifieds is a growing niche.
In 2003 the market for classified advertisements in the United States was $15.9 billion (papers), $14.1 billion (online) according to market scientist Classified Intelligence. The worldwide market for categorized ads in 2003 was approximated at over $100 billion. Maybe due to the absence of a requirement for reporting, market statistics vary concerning the total market for internet classified ads. The Kelsey Research Group noted online classified ads as being worth $13.3 billion,  while Jupiter Research study provided a conservative appraisal of $2.6 billion since 2005 [citation required] and the Interactive Marketing Bureau noted the net worth of online free classified classified income at $2.1 billion as of April 2006.
Paper's income from classifieds ads is reducing continuously as internet classifieds grow. Categorized marketing at a few of the bigger paper chains visited 14% to 20% in 2007, while traffic to classified websites grew by 23%.
As the online classified advertising sector develops, there is an increasing focus towards specialization. Vertical markets for classifieds are establishing rapidly together with the basic market for classifieds sites. Like search engines, classified sites are frequently specialized, with websites supplying marketing platforms for specific niche markets of purchasers or sellers.