As in many other situations involving asymmetric power relationships, VC’s (who usually have the power) like to preserve optionality with startups in which they’re interested (as I wrote here). That is, VCs generally will try to keep interesting deals “on the hook” until they have to make a decision (usually driven primarily by the concern that other VC’s are converging on the deal). From the VC’s POV, this is eminently rational. Why make a risky decision (i.e., whether to invest) until you have to – waiting may allow more data to emerge that will inform/improve your decision. Accordingly, VCs, good ones anyway, become quite skilled at saying things, whether or not true, that make entrepreneurs think there’s serious interest in their deal.
For the entrepreneur, this frequently leads to disappointment.
Experienced entrepreneurs know that they cannot rely on anything a VC says about where the VC really stands. As I wrote here, the only way to tell if a VC is interested in your deal is whether they are re-arranging their schedule to work on your deal. If you're not pushing other stuff off their calendar, you're making no progress. Whenever a VC misses a deadline in getting back to you, it’s a bad sign. In general, given how time-consuming the fundraising process is, the entrepreneur should consider that VC a “pass”, and focus fundraising efforts elsewhere.
As an aside, in the roughly 20 years I spent as a lawyer representing entrepreneurs, I used to tell my clients that the worst curse they could inveigh against a competitor was that the competitor had to seek venture financing. That guaranteed that the management team of the competitor would have to take their eye off the ball for 3-6 months.
Even “scheduling-altering behavior” by the VC, however, is not always a good indicator of an eventual offer. Many deals evoke an initial burst of activity by a VC (especially if the deal is perceived as “hot”), only to have the activity level fade and turn into a “pass”. Not infrequently, in my experience in representing entrepreneurs as their lawyer, the last thing an entrepreneur may hear from a VC before “We’re going to pass.” is “Would you consider raising a bigger round, so we could write a bigger check?”. The only certain way (as I wrote here) for entrepreneurs to know their deal is closing: when the VC’s wire transfer hits their account. Until then, best to remain skeptical, and keep plugging.
Further aside: VC’s often (indeed, most often for the vast majority of VCs) “communicate” that they’re not interested in an entrepreneur’s deal by going radio silent. The most frequent lament from entrepreneurs is that most VC’s with whom they have met never get back to them, despite promising to do so. This leads to the final lesson of this post: if you have twice written to a VC, without reply, it’s a pass, and you should move on. For some reason, it’s a hard lesson for many VCs to learn that the second-best answer to an entrepreneur is a quick “no”, even with no explanation. For entrepreneurs who are fundraising, open loops are mentally and emotionally draining, so the fewer the better.