Corporate venture capitalists were known during the dot-com bubble for pouring funding into startups because they thought it was fashionable, earning themselves a reputation as dumb money. "That was not an unfair label," says Anand Sanwal, CEO of the New York-based investment research firm CB Insights. But these days, for many corporate VCs, that label would be unfitting.

The number of active Corporate VCs--which serve as the investment arms of giant firms and include Intel Capital, Bloomberg Beta and GE Ventures--has grown by 15.5 percent year-over-year between 2011 and 2015, compared to a growth rate of 12.8 percent overall for VCs of any type in the same period, according to data from CB Insights. Sanwal attributes the growth in part to the realization among large businesses that they can't innovate on business models or develop new technology as quickly or with as much nimbleness as a startup.

With the presence of investing arms of corporations growing in the VC world, startups can't ignore the potential source of money, says Silicon Valley startup incubator 500 Startups partner Emily Chiu. There are other strategic reasons to consider these firms too, suggests Chiu and Sanwal. Here are three: 

1. You need the relationship.

Chiu says that often when a startup considers seeking funding from a corporation, they do so at the last minute when they're desperate. It's an approach with a high likelihood of failing. "It's not like they're just blindly throwing things around," she says of corporate VCs. If a corporate VC is interested in investing, take the interest seriously because you may need their help down the line, or you may want them as a customer.

2. It matters for your exit strategy.

Most startups fail. Among those that succeed, most exit via merger and acquisition, says Chiu. The idealized path of raising funding from traditional VCs and then making an initial public offering is trodden by a select few. So when it comes to corporate funding, "You have to be in a really privileged position to say 'I don't need it,'" she says.

3. Corporations want you to succeed.

It can be tempting to cast corporate VC funding as dumb money by definition, but that would be simplistic. While these giant firms look at startups as takeover targets--to keep their innovation engines humming. As an investor, they also have an interest in seeing your company thrive. So, in a sense, they might be even more motivated to be helpful than a traditional VC.