Does the revenue model of most content providers comes down to ads?

It is not necessary that adverts bring in the maximum revenue for a content provider. There are various avenues available for a content provider to bring in revenue:

• Content creation for brands of products and services which need such support. The key here though is authenticity and believability for the consumer of this content
• Traffic re-direction offers another method which can generate revenue from the sites which value the eye balls and attention you send in their direction
• Premium paid for content (especially if it is a speciality domain) is another avenue

These are just a few options. There are more, quite often tailored based on what the business is actually about. Essential for any content provider is to model its revenue generation based on the simple but critical question - What is in it for me? - be it for a content consumer, a content generator, a content requirer or a content forwarder.