When a VC decides not to invest in your company they may offer to send your executive summary to another VC.

As I mentioned in my post, Why You Might Not Get The Meeting, your business must meet three high-level criteria in order to be an investment candidate:

1. A viable, high growth, scalable business
2. A good investment, capable of a large return
3. Aligned with the fund’s investment criteria

If a VC does not think your venture is an attractive business, he will not distribute your business plan. He won't want to waste the time of other VCs.  Similarly, if the investment return is not aligned with the requirements of other investors a VC may not circulate the opportunity. It's worth noting that investors have different return requirements and therefore if your idea is not a fit for one VC, it does not mean that another investor couldn't be interested.

If the only issue is a misalignment with the VC's thesis, they are more likely to offer to share your executive summary than if it doesn’t meet either of the other two criteria. However, this is only the case if they know a VC that they think may be interested. The probability of him knowing potentially interested investors is typically higher if your business plan is more closely aligned to his investment thesis. VCs tend to know the other folks in their space. For example, as an IT guy it's less likely that I will be able to help a real estate startup than I would be able to help an IT venture.

The bottom line:  VCs are most likely to pass executive summaries to other VCs when the business plan is both very strong and very relevant to that VCs investment strategy.