Thanks for clearing the air. IMHO, the only way to make SI purchase successful is to have the GM business plan. One site could be the Chevy and the other a Saturn or GMC. For example, one could have access to traditional features and the other premium features. Every poster has different styles and preferences and this will cater to both. Try not to be redundant with the sites since many are here for various reasons.
When you present to advertisers you can offer packaged deals since posters don't mind seeing the same advertisers. I hope everything works out for you and I wish you good luck with your new purchase.