I actually have the feeling I can make some money because

a) people already donate (the donation ratio is around 10%)

and

b) adsense already generates revenue enough to, at least, pay the service costs and buy beer :-)

The service actually already allows you to embed the map on any site (in an iframe model or just putting a banner with a popup) - the average user of the service has usually not a lot of experience with html, so I provide the snippets on the site itself to make it easier for them.