Internet is a very useful tool for the markets investigation from the moment in which it facilitates an immediate relation with the possible informants (interrogated persons, disputants, etc.), independently of the geographical place of the investigator and of the informant.

Well used, this tool can contribute a reduction of costs and of period of execution in the market researches. The companies face a new revolution in the form in which they have carrying out his activity, both as for new products and offered services and in the novel way of the commercial and professional relations appearing with the clients.

The sector of investigation of markets in the USA has been sensitive to these changes significantly rather than in Europe, taking clearly the world leadership on the subject of investigation on line.

The integration of all the processes of the traditional investigation (design of questionnaire, data capture, statistical treatment and results presentation) in a new interactive way is going to renew the way of acting with the client and the service that gives him to itself. Also the mobile connected to Internet points like an investigation way with big possibilities.

Although in Spain it is a slightly mature activity, we think three basic uses of Internet a reference in investigation:

• Informers' panel. A wide group of informants (consumers, specialists, viewers, etc.), previously chosen and recruited for the study, provides to us the information that we wish, by e-mail well well across a web page.
• Questionnaire "hung" on the network. We place a questionnaire on a web page and provoke the voluntary answer encouraging it with some type of compensation. The place of the questionnaire and the links that they hire to provoke his visit are fundamental to select the type of wished informant and to obtain a high number of answers.
• Questionnaire mailing by e-mail. If he gets ready of a file of electronic directions of persons or companies that we wish them to answer to our study, the e-mail can substitute the classic postal survey. It is important that the informants to whom the questionnaires are sent have been prewarned or have accepted previously the participation in the survey. (The massive and "blind" questionnaires mailing by e-mail can be considered to be a spam practice).

The Home advantages of the investigation across Internet sound:

• The intermediary's absence between the questionnaire and the interviewee does that the opinion polls are more objective. In principle, I think that it is a cheaper method.
• The interactivity of the client with the institute will be major, since the determinant of the interviewer is avoided, printing even major rapidity on the treatment of the answers and his later tabulation.
• Rapidity in the collection and data analysis.

The Home disadvantages of the investigation across Internet sound:

• The difficulty of access to certain types of informants between whom his use is still not extended.
• The difficulty in controlling the informants' selection (for example, to prevent the same person from answering several times the survey, to make sure that the person who has answered is the suitable one, etc.).

There is – finally – a type of studies that we consider to be more «investigations on Internet» that investigations based on Internet. We refer to the audience researches of web pages, to the studies on profiles and behaviors of the Net user (average visit times, types of required information, etc.).