Domain Monetization Models
When "domainers" began buying domain names in the 1990s, the only way to earn money was to build a full-blown website with banner ads or membership fees, or to "buy low" and hope to "sell high." Domain owners had to pay the annual renewal fees on their domains without any income to offset the fees; and this set limits on the size of portfolios. Some domainers were forced to let domains drop every year.
The development of pay-per-click ads - in the form of AdSense and domain parking companies - changed everything. Suddenly domains could earn the few pennies a day that they would need to break even. Domain parking continues to be the easiest way to monetize a domain name, but other models are beginning to compete more strongly.