its a trip though because shit like HSD Kenichi was very popular! And IPPO, i was soooo pissed that it randomnly ended. But there are other issues besides popularity--some anime start when the manga has only gotten 15-20 chapters, so to make episodes weekly it'd catch up to the manga in only 7 episodes, so they pretty much make the anime a completely seperate entity from the manga. also, some anime will start with the manga quite far ahead, but then maybe the manga goes on hiatus for some reason or start getting published monthly rather than weekly so the anime would quicly catch up if the anime was staying true to the manga storyline. stuff like Onii-chan no Koto Nanka Zenzen Suki Janai n Dakara ne! has an anime when it only has about 30 chapters right now--this happens a lot with ecchi/romance manga... The anime starts right away with a decidedly 12 or 24 episode contract and is not based on popularity