I'm building a service for putting public sites behind custom URLs, plus adding analytics, CSS, metatags, etc.

It's essentially "reverse proxy any public site" as a service, with some Lambda@Edge functions sprinkled on top to inject analytics, CSS, etc.

A typical use case would be something like "make your Trello roadmap available at roadmap.yoursite.com instead of trello.com/b/fsyFS8w3".

It started off as a fun little technical challenge, but I've managed to get some customers and tonnes of feedback.

I'd love to squeeze some wisdom/advice from some of the more experienced members of the community: Is this idea viable in the long run from an AWS cost perspective, if charging monthly? Are there any legal concerns behind offering a service like this? Any general tips for someone getting their first few side projecft customers?

Any other general advice would be much appreciated :).

For reference, the service is: https://cloak.ist/