Read and write data to a webserver or...?

I am attempting to recreate a heatmap tool that was recently dumped by GameAnalytics. I am able to write and read text files in my editor using StreamWrite and StreamRead. I want to make a webplayer version and ideally have the player position recorded during gameplay and then display as a heatmap on the end screen. The best case would show a map of all collected player positions over multiple play throughs.