We attract a lot of customers because our platform is free to use, and our Basic plan boasts many features. However, there are features we provide only for paying customers. These features generally incur more overhead on our side, so we finance those overheads with subscription fees.
Some premium features open to all premium accounts are searches further back in the archives, unlimited watchlists, more topics allowed per watchlist, and special topics like Constituents of the S&P500. Oh, and there's no advertising on our site or platform. We wouldn't ask you to pay us then bombard you with advertisements to make a few extra bucks. In fact, for some partners, we've even removed the advertisements from their websites (when viewed through our platform, of course) - this last feature requires our highest tier subscription, though.
There is also some gradation within premium accounts, and you see how they differ on this page. Some Gold features include machine translation, paywall-free content for some publications, deeper archive searches, and offline reading, but Silver is not a bad deal itself. You can see current prices, discount offers, and live features on the pricing page.