Quite a few things to identify here Brice E.:
I would start with figuring out if I was talking to the decision maker and someone who has the authority to write the cheque or someone who simply manages the decision. The former are the people you want to talk to.
I've found that 2 things work really well when the momentum slows down: 1. Remind them they were interested. Follow it up (in the same message you send) with a straight-foward question like "What do you want to do about it?" or "I have some time Tuesday at Y. Why don't we take a few minutes to explore this further?" and 2. Send new insights that either solves a problem they have already mentioned or shifts their mindset on a solution they weren't thinking about. Be really specific and mention where in conversation they brought it up. This positions you as their expert in their mind.
And yes, in B2B, especially the bigger the company, building relationships with 5-7 people is the best bet so the momentum doesn't slow down as much.
To sum it up, be assertive, remind them they were interested, and ask for a decision within a stipulated deadline. That kickstarts the conversation.
