Almost everybody gives credit to Intel for popularizing the term netbook – when the Asus Eee PCs first started showing up, they were being called sub-notebooks, sub-laptops, mini-notebooks, UMPCs (which really confused things, as UMPCs generally had a specific form factor that they followed), ultraportables, lightweights, etc. Basically, there was a heckuva lot of confusion among various companies and various websites over what to call these devices.
Intel stayed consistent in their labeling them “netbooks” and some manufacturers followed their lead.
In what appears to be a show of confidence in the form factor, it’s now come out that Intel has bought netbook.com (how much, we don’t know).