.netCHARTING web (asp.net) based licensing is available per web site or per server. If you use a centralized system for chart generation, such as a dedicated charting server, license purchases are still required for each site / server that consume that service or ultimately display charts generated from the central server.
In other words, centralizing chart generation will not reduce the licensing requirements. In all cases a license purchase is required for each web site and/or server the charts are displayed on regardless of the original system that generated the chart image.
If your usage requires both web (generation or display through IIS) and winforms (windows service or offline / batch generation) a license purchase would be required for both the WebForms and WinForms products.
We offer OEM options are available high use SaaS environments. Please contact orders@dotnetcharting.com if you have any questions regarding bulk license purchases.