virtual ISP(n.) An ISP that piggybacks its services off of a third-party provider in order to offer ISP services without the expenses and duties required in providing those services. The virtual ISP does not invest in any network, equipment or backroom/technical support needed to offer ISP services. The third-party provider handles all of the needs of the end user but is invisible to the end user who only sees the virtual ISP.
For example: Company A is an online retail bookseller that wants to extend its services to offer its customers ISP services to bring more value to its customers and to create a bigger brand name in the market. However, the company, being a retailer, does not have the resources to branch out into the ISP arena and therefore hires Company B, an existing ISP, to provide the ISP services. Company B creates a branded ISP for Company A so that Company A's customers think that they are getting their ISP services through the bookseller but in reality they are being provided the services by means of Company B, the real ISP, who remains invisible to the end user. In this way, Company A becomes a virtual ISP.