I have nothing against a company trying to make an honest dollar in exchange for a useful service. After all, that is why companies are in existence. Those internet companies which provided free services and based their existence on supporting those services with advertising are having a tough time right now. The advertising model is based upon network television's success at providing free programming in exchange for viewing of advertisements.
The most significant issue with this model (on both television and internet) is fact that customer is not viewer or user. The customer is advertiser. The actual user of service is commodity which is being sold. That's why Neilson ratings are so important to network stations - they determine how many viewers are watching so that commercial time can be sold. The higher rating, more likely sales are to occur and higher rates can be.
The model gets even more convoluted with services such as GeoCities and Egroups. You see, model normally has three components: company selling advertising (such as Yahoo), advertisers (the real customers), and users (the viewers of ads). Egroups and GeoCities adds a forth grouping.
This is content providers. In network television, content is purchased directly by networks and carefully planned to be of maximum desirability to advertisers. In case of Yahoo and similar companies, content is created by a legion of volunteers, all more or less industriously working to make money for corporate machine.
Who are these content providers? Why, anyone who has a web site (in case of GeoCities) and runs a mailing list (in case of egroups). As you create web pages or send emails you are actually giving content to company, in which they place advertisements. People look at your content and view ads.
Unfortunately, in this model content providers are not worth much to company. After all, there are plenty more where they came from. Someone will always want a free web site or mailing list or whatever in exchange for showing of ads.
That is main reason why service from companies with this model tends to be exceptionally poor - content providers are lowest critters on food chain.
This is very easy to see. Let's say someone puts up a web site on one of these free providers which has some questionable content, perhaps not exactly in violation of terms and conditions but it could be interpreted that way. You will find that web site will be deleted immediately and without warning on first email complaining of a violation. There is usually no investigation, no appeal and no recourse for webmaster.