i actually view it more like the standard age old pricing model for goods with massive supply. "Content" is drastically higher in supply than demand, you are simply paying your market price for content. Ads would of course exist, but largely yahoo and early portals acted as print media companies selling advertising instead of content because 1) it was a new dist model, 2) there was nothing close to the ecomnerce and payment tools.

So basically, you are just paying for the goods you use, you set your price and this is beneficial to companies because the marginal cost of serving a webpage is almost nothing so if you opt to pay anything it is profit.

Unfortunately, taking time to pay for something has more friction than just not paying for it as well as being cheaper.