Based on your financial expertise, provide your response or viewpoint on the given financial question or topic. The response format is open.

Main source of the shares/stocks data on the web
The main source is a direct feed from the stock market itself. The faster the feed, the more expensive. 15-minute delay is essentially free... and for those of us who do long-term investment is more than adequate.  If you want data sooner, sign up with a brokerage that provides that service as part of what you're paying them for... and remember that every bit you spend on services is that much more profit you have to make just to break even, so there's a real tradeoff.