Reaching Enterprise Customers

Currently, I am looking into a SAAS idea in the requirements management space.

The market is dominated by a few big players like IBM Doors, Simens Polarion, and Jama. Users of such applications are usually also big companies because they operate in regulated markets like medical, automotive, and alike.

I wonder if any of you have experience reaching such clients? I am wondering if setting up a landing page would even be worth bothering with. My impression is that these companies change slowly.

I like to be proven wrong by your experience!