The new law does include safeguards, given its restriction to accredited investors (people with a personal net worth of more than $1 million or who make more than $200,000 in annual income).

Eventually, however, a revision that is expected to be approved will lower the restrictions around the definition of an accredited investor, meaning more of the public will have a chance of investing their own money into companies that they believe could be as big and successful as Facebook or Twitter.

Although it is not yet known when that will happen, Mr. Agrawal said it could lead to “the wild west” in crowdfunding.

Most people are familiar with the idea of crowdfunding through sites like Kickstarter and Indiegogo, which have made headlines for helping average Joes and Janes drum up attention for their ideas and raise thousands, sometimes millions, to finance them. But financing through those sites differs from what the new JOBS Act provision allows, in that the sites solicit donations, not equity investments.

Occasionally, the people who pledge money to back projects listed on these sites get a “reward,” or a tangible memento in return for their contributions. For example, people who gave $99 to support the Pebble smartwatch project on Kickstarter were promised a device fresh off the assembly line.

Kickstarter, founded in 2009, says close to $800 million has been pledged to about 104,000 projects on the site. But some projects have raised large amounts of money and struggled to produce their promised goods or services, although it is difficult to say exactly what the failure rate is. Kickstarter does not share details of either the success or failure rate of projects financed through its site.

One problem for the crowdfunding sites has been that getting the money is often the easiest part. It is another matter to turn the rosy projections of business success into reality, especially with a crowd keeping an eagle eye on the progress. The Pebble watch, for example, had problems in production that delayed shipments by weeks. Another Kickstarter project, started in 2010 to make lock-picking sets, is still struggling to manufacture and ship sets to those who donated money to receive one.