1. One sponsor per blog.
2. One niche per blog - but in the end i sell 'em the multisite thing, so they get what they like/want PLUS what they're curious about and this and that (the irresistible offer).
3. I make up my own posts (about 300 words per post).
4. Do you mean the meta description? If so, it is totally irrelevant regarding seo - BUT since it's the second most prominent item in googles results, it DOES affect your CTR (from G to your site, that is).
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