Gross margin = (Revenue - COGS) / Revenue. So reason is very low costs... being that there is almost no physical inventory/material costs involved. Just serve

Gross margin = (Revenue - COGS) / Revenue. So reason is very low costs... being that there is almost no physical inventory/material costs involved. Just servers, a few programmers to make and maintain things, any other staff, and whatever bills they have (e.g. electricity/internet/advertising/fees from software they use).