Tips to attract corporate stays

The area my listing is located in is a hive of corporate HQs and is a capital city. Yet, I've been having a surprising (to me) lack of corporate enquiries or even extended stay enquiries.

The listing offers competitive amenities for the area, is large enough for 4 people across 3 rooms, and is priced 30% below comparable properties when booking for 15 days or more and 50% for 28 days plus.

I've been thinking of doing some emailing of STL/relocation agencies and even corporates directly to just improve my visibility. The listing has no stays and no reviews as yet, but I operate a duplicate listing, with one bedroom less at higher nightly prices and have had quite good bookings (3 night average stays) with 5 star reviews.

What tips might you suggest if you successfully attract such guests?