Ads in a paper are usually short, as they are charged for by the line or word, and are one newspaper column large.
Publications printing news or other information frequently have actually sections of classified ads; there are likewise publications that contain only ads. The advertisements are organized into classifications or classes such as "for sale-- telephones", "desired-- kitchen area devices", and "services-- plumbing", hence the term "classified". Categorized ads typically fall into 2 types: people marketing sales of their personal goods, and advertisements by regional services. Some organisations use categorized advertisements to work with new workers.
One issue with paper categorized marketing is that it does not allow images, despite the fact that screen advertisements, which do allow images, can be found in the classified section.
In the last few years the term "classified advertising" or "classified ads" has actually broadened from simply the sense of print ads in periodicals to include similar types of marketing on computer system services, radio, and even tv, especially cable tv but sometimes broadcast television as well, with the latter occurring typically very early in the early morning hours.
Like the majority of kinds 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 discovered the benefits of classified marketing.
Web classified ads do not typically use per-line rates designs, so they tend to be longer. They are also searchable, unlike printed product, tend to be regional,  and may promote a greater sense of seriousness as a result of their daily structure and broader scope for audiences. Since of their self-regulatory nature and low cost structures, some business provide free classifieds globally. Other companies focus mainly on their regional hometown area, while others blanket metropolitan locations by utilizing postal codes. Craigslist.org was among the very first online categorized sites, and has actually grown to end up being the biggest classified source, bringing in over 14 million special visitors a month according to Comscore Media Metrix.  A growing variety of sites and business have begun to supply customized classified marketplaces online, dealing with niche market items and services, such include boats, pianos, animals, and adult services, among others. In many cases, these specialized services offer much better and more targeted search abilities than general search engines or basic classified services can supply.
A number of online services called aggregators crawl and aggregate classifieds from sources such as blogs and RSS feeds, instead of depending on by hand sent listings.
In addition, other business supply online marketing services and tools to help members in creating online advertisements utilizing expert advertisement templates and then automatically dispersing the finished advertisements to the various online advertisement directory sites as part of their service. In this sense these business act as both an application provider and a material delivery platform. Social classifieds is a growing specific niche.
In 2003 the marketplace for classified ads in the United States was $15.9 billion (newspapers), $14.1 billion (online) according to market scientist Classified Intelligence. The worldwide market for classified advertisements in 2003 was estimated at over $100 billion. Perhaps due to the absence of a requirement for reporting, market stats differ concerning the overall market for web classified advertisements. The Kelsey Research Group noted online categorized ads as being worth $13.3 billion,  Click here while Jupiter Research study supplied a conservative appraisal of $2.6 billion as of 2005  and the Interactive Marketing Bureau noted the net worth of online classified earnings at $2.1 billion since April 2006.
Newspaper's revenue from classifieds advertisements is decreasing continually as internet classifieds grow. Classified advertising at a few of the bigger paper chains dropped by 14% to 20% in 2007, while traffic to categorized websites grew by 23%.
As the online categorized marketing sector establishes, there is an increasing emphasis toward expertise. Vertical markets for classifieds are establishing rapidly in addition to the general marketplace for classifieds sites. Like browse engines, categorized sites are frequently specialized, with websites providing advertising platforms for specific niche markets of buyers or sellers.