There is an exploit that players owning the Compendium - well, at least the Russian ones - seem to be using extensively for the last couple of weeks. They use certain high ground spots in a passive bot match to get exp from creeps while staying afk, eventually getting account experience and items. There also seem to exist some variations and tactics regarding what heroes to pick and what lanes to push\control. Googling it (well, in Russian) gives plenty of results for steam group invites and even guides on the SteamCommunity forum. Some guides even cover how to do it solo having 5 dota accounts. It looks like this exploit had been used before as well, but it became more relevant with the Compendium battle bonuses.
Some match ID: 204892875, 204468048. 205460510