“How to close a sale?”
Ask your customer, not me.
I’m not trying to be abrupt, but it sounds like you’ve already done all the right things and your relationship with your customer should have reached the point where you can ask them exactly this question.
Dealing with institutions can be it’s own animal. The best way to learn how their buying process works is to ask them! In a perfect world, you may still be 6 months away from a sale. You wouldn’t agonize over it if you knew, and you’d know if you asked.
In dealing with institutional customers, I even take it a step further. Before I invest any time in the sales cycle, I have them teach me what it takes to get a sale, exactly what I have to do, and how long it will take. Real buyers will be happy to tell you all of this; in fact, they may think you’re sales amateurs if you don’t bother to ask. Lots of times the buyer may be frustrated by their own organization and will coach you to be more successful so that they can get what they want.
There are millions of potential tips: “You have to talk to Joe Smith first.” “Never call Fred on Monday.” If you filled out Form XG7-B first, you’ll save 6 weeks.” “Mary only buys from people she meets through Bill or her Business Group.” “You have to be a preferred vendor of XYZ..”
I hope you get the picture. Like I said, it sounds like you’ve done all the right things so far. No one here at hn knows what else you need to do. Your customer does. Ask them. Today.