When i sold my online book store in the UK several years ago i actually had the business appraised by a licensed accountant.

From what i recall, the sales price took in to account a lot of factors that i wouldnt have even thought about including:

Actual assets (stock and equipment)
Previous earnings from the company.
Market pricing for similar businesses to mine.
Future earnings based on residual clients i had. (This is specifically important to those of us looking to sell 'recurring' membership based sites, if you have 1000 active recurring members at $29.95 a month, you dont sell the site based purely on previous sales figures!).

So far as finding buyers, the absolute best type of buyer you can find is one who runs a site similar to the one you are looking to sell, someone who can incorporate your existing business in to their long term business plan with ease. In the case of CBL for example, you would want to contact all the other cam houses and feed providers, gay and straight.

So far as 'what' you sell, you sell your company name and its assets, after you have tried liquidating some of the assets yourself, i would presume you have cameras, hard drives, computers, etc laying around, liquidate these before getting your companies appraised value

Regards,

Lee