Embed.rocks was created by Ilkka Huotari (ilkkah.com). It was a by-product of a social network (chttr.co).
The pricing model for Embed.rocks is important — the customer pays only for the resources, i.e. some sum per fetched url. There is no monthly fee. The reason for this pricing model is that it is very fair for everyone, which is an important principle to the site's founder in life in general.