Online video sites continue to rack up millions of dollars in funding, as investors seemingly trip over themselves to place big bets on startups they hope will challenge market leader YouTube.

The final exclamation point to a long, hot summer came Friday, as the French YouTube clone Dailymotion announced a $34 million second round of funding, capping a summer of mega-financing for YouTube-ish companies that totals more than $200 million.

In May, Luxembourg-based Joost announced it had raised $44 million for its downloadable software that shows channels of professionally-produced video. Then San Diego-based Veoh scored $26 million for a video sharing site and downloadable software that allows users to find and download video from around the Internet. And just last week, the Palo Alto, California-based Metacafe unveiled a $30 million funding round for its video sharing site that offers money to amateur video makers.

Meanwhile, NBC Universal and News Corp.’s yet-to-launch home for professionally-produced video on the web (since named Hulu), took home a $100 million round of private equity, for a reported total valuation of $1 billion.

Dailymotion, one of the fastest growing video sites on the Internet, raised its second round from AGF Private Equity and Advent Venture Partners, CIC Capital Privé, as well as existing funders Atlas Venture and Partech International.

The question these startups face is whether or not online video, expected to become a $3 billion advertising market by 2010, can justify this latest venture capital craze.

“I’ve seen this before, where people say that something is going to be big, therefore every site that’s doing well must become a success, and that’s not the case," said Forrester analyst James McQuivey. “Just look at Buy.com.”

The key, say analysts, will be for each of these now well-funded companies to distinguish themselves from one another—and more importantly from YouTube—so they can validate their investors’ bets.

The Paris-based Dailymotion, for example, has created separate video sharing sites for nine countries in Europe and North America, with language and content tailored to each specific region. That’s a strategy that YouTube has only just started tackling.

“All of these sites say they’re not just another YouTube, but I think one of the simplest to justify is the international play,” said Mr. McQuivey. “If you can tailor a content and ad sales strategy to serve Europe, that seems like a pretty obvious model that is different than YouTube.”

In addition to rolling out sites in more countries by the end of the year, Dailymotion plans to unveil in-video advertising and a content creator revenue sharing program, said a spokesperson Friday.