Attention and interest on the web are critical metrics and are an essential component that should guide any online strategy. LinkedIn has done an excellent job in this area of indicating interest quantitatively. Let us look at a few examples:
Indicating interest in you/your profile by showing how many looked at your profile. Indicating interest in a job by showing how many people clicked on the Apply button. Indicating interest in your connections by showing how many changed jobs in a year.
There are some other examples in the online retail industry. For example, Rue La La indicates interest in their products (clothing, accessories, home goods, etc.) by letting us know how many Ralph Lauren sweaters are left to buy thus indicating how quickly a product is getting sold. We also measure interest (though not shown quantitatively) by grouping stuff under most popular, most commented and most shared on various blogs and news sites.
The theme of the third largest social network, Pinterest (Facebook and Twitter are the top two) is centered around interest. Interest is indicated quantitatively through likes, repins and comments. We need to have a measure of interest by consolidating our online behavior (sharing, commenting, viewing, etc.). Let me know if you have any ideas on how to measure interest.