Ask HN: 4 of 24 VCs showed interested -- what now?

Background info: we launched few months ago and we're growing like hell traffic-wise, team is great and experienced, product is innovative and has a strong fan base. Sent 24 mails to VCs (most were cold) and 4 replied. Each of the 4 replied instantly like one day later. Each thinks about next steps, is still checking our product or wants to meet us soon. They have one thing in common: after the initial reaction they seem to let time lapse away until the next step. I think they all act by the principle of late-decision-making.

They are smarter and more trained than me regarding such deal processes. So, how can we push them or initiate an authentic "bidding war"?