Is there a dataset describing the #employees, #customers, revenue, investment etc for web company such as google, mozilla, yahoo, facebook?
WIKI has few information like #employees, revenue. Querying SPARQL with DBpedia may extract it. However, the information is few.
Yahoo! finance has much more information, using Yahoo! finance API with company symbol (using fb for Facebook for instance) can extract this information if knowing the company symbol in NASDAQ stock market in advance.
But it has drawbacks. NASDAQ doesn't contain company outside the U.S and outside the stock market. For example, deutsch tekecom in the former case and Mozilla in the latter case. The former case can be solved by considering more than one stock market but it will face the problem of redundancy. Ex. Facebook in London stock market , Facebook in Germany stock market, Facebook in NASDAQ and so on.