If you're coming from anywhere else, like an ad, it's going to be linked to a landing page tailored to that source. For example, if you search "A/B testing" on Google, you'll find an ad that links here, not to their homepage: https://www.optimizely.com/ab-testing
[1] Super over-simplified rule of thumb: If you see "Solutions" in their nav menu, it's enterprise software.
As the target audience for Optimizely and an ex-customer, I have to say it annoys me to no end that they are so light on details. My time is limited and I don't want to have a conversation with a rep until I can see more of what it offers. Pretty much every analytics platform out there falls into this trap.
Half the time the sales reps can't even answer my questions so I have to waste even more time with a sales engineer on a followup call to just see basic things like pictures of the interface.
Their original product was pretty straightforward: easy-to-use A/B testing. Put in your site, drag and drop some stuff, click go, and it'll tell you if one version performed better. Their old home page reflected this, and mostly tried to get you to take it for a test drive (you could enter any URL and play around with it).
The new product is MUCH more upmarket. They're looking for companies that have enough traffic that you can cut your visitors 5 different ways and still have a meaningful segment to market to. Between this and the fact that it's new news, the homepage is deliberately information-light. They know you know them, and they want to get on the phone.
My prediction is they drop back to something a bit more interactive / descriptive once the buzz from their raise and launch dies down.