To become a verb is a major success for a centralized web company. The goal of any ambitious startup is to no longer be a name, but a thing someone does (e.g.: I googled a recipe that I tweeted to my followers before ubering home.) In a shallow sense, it is a success because the company has cornered their market; they've inhabited a need so fully that their name is synonmous with the need itself. In a deeper sense, it is a success because, in the act of becoming a verb, the actual company disappears.