Currently, most financial websites such as Yahoo Finance (finance.yahoo.com) and Google Finance (finance.google.com) only display, show and stream delayed stock quotes of up to 20 minutes for NYSE and 15 minutes late for NASDAQ’s stocks for free. If you’re want streaming live and real-time share prices and stock quotes, you will normally need to open a stock trading brokerage account or day trading account and pay a nominal fee for the live access. Other self-claimed live quotes or real time share prices providers websites normally only offers real-time ECN quotes, or limited time period demo or evaluation live quotes.
If the real-time live shares quotes streaming is been offered according to previous Google products such as Gmail, Google Analytics and Google Earth, then it will likely to be free too, where Google will absurd fees, charges and costs in providing the service, in exchange to mass user base and goodwill or earn revenue via advertisements placement. Google Blog post has providing conflicting information on whether the free stock quotes service will be free or not. On one hand Google wants to “ensure that this data can be made available to our users at fair and reasonable rates”, while on the other hand, Google promises “you’ll have free, easy and fast access to real-time prices from NYSE on Google.”
Anyway, if live streaming stock quote service is offered for free by Google, other financial service providers likely to follow suit too, in a similar way to how other webmail services responded to Gmail. This is especially true and possible as the case that Google proposed to SEC, once approved, will likely apply to every companies or organizations that extract or download the data from stock exchanges.