I implemented a facecam into my videos for a few weeks this summer to try it out and had mixed feedback from viewers. Some really liked it and others were annoyed it was blocking part of the screen. (I put it in the least invasive spot usually though). Anyways I stopped using it for most my gaming videos, but still would bring it back for videos where I thought the audience wanted to see my reaction or special clips. It's not a bad idea to build your "personality", but it is possible they may not like it as well.