Selected answers from the Dumb SEO Questions G+ community.
Ranu Jain: Using "keywords" does not look natural and it might be treated as an attempt to game SERPs. This can inversely affect your site. ;<br /><br />So, would recommend you to use name rather than keywords in that specified field. ;
Rajesh Kumar: Thanks,but If we use username then it get promote username rather than keyword. so what its benefit?
Rajendira Prasad K: User name should your name, So many people will know you, connect with you, discuss with you, community get bigger, Community makes brand awareness.
Ranu Jain: Yes, it will look natural and genuine. On top of that, it will minimize the chances of getting affected negatively. I think that's the biggest benefit. ;
Bala Sathya Narayanan: you could use the keywords in comments or in reply boxes,but it shuld be in a flow nd not in an intention to add the keywords...