New research from Nielsen/NetRatings reports that roughly half of all Web users visited a social networking site in April, the highest output yet, as the social networking phenomenon continues its meteoric rise to mainstream media consumption. Year over year, the top 10 sites grew 47 percent in the U.S. to 68.8 million unique users, reaching 45 percent of active Web users. MySpace, of course, greatly inflated those numbers, topping the list with 38.4 million unique users and a--get this--367 percent growth rate. Google's Blogger came second with 18.5 million uniques and a not-so-bad 80 percent growth rate. Classmates Online came …

So ABC and "Desperate Housewives" have started the free, ad-supported streaming media trend, but is the Internet ready for it? No, says the Associated Press. Running small clips on YouTube is one thing, but what about longer streams at HD-quality? Not a chance--not yet, anyway. Most home Web use still comes in small bursts, an e-mail or news story here or there, a couple IMs, etc. A two-hour movie is out of the question, however, not until ISPs seriously beef up the bandwidth capacity of their networks. And that's going to cost a lot, which is why ISPs like Verizon …

A nasty little secret that's leaving advertisers exposed has emerged recently: many ad networks don't care about the quality of their referring affiliates, they just want to grow their networks. As ClickZ points out, when massive publishers like Yahoo outsource ad buys to their affiliates, "quality control can be greatly diminished." Publishers do this because it can be lucrative and hassle-free for them. Networks do this for largely the same reasons--but to be fair, legitimate outsourcers are always unaware of sub-affiliates that deal in spyware and porn. Some advertisers looking for volume might not care as much about brand impact, …

Bill Gross, the man who brought pay-per-click advertising to Google and Yahoo, has started a new search engine that will sell text ads marketers pay for only when customers buy. With Snap, advertisers bid against each other on what they would be willing to pay if a customer completes a certain action--like buying a product or registering at a Web site. They pay only for these conversions. For some advertisers, PPC ad returns have been diminishing, so a new scheme like this will be welcome. It will certainly be interesting to see how a search market based on conversions settles. …

Microsoft and Yahoo both bowed new search advertising systems this month. Google just launched a slew of new services--some of which are search-related?at its press day last week. Despite Google's overwhelming lead, the search wars are far from over; or its competitors, at least, are far from giving up. MSN and Yahoo both lost market share last year, according to comScore: Google had a 43 percent share, versus 28 percent for Yahoo and 13 percent for MSN. The search giant won't be getting too comfortable about its spot at the top, not when Microsoft says it's putting $6 billion behind …

An overwhelming majority of young adults--86 percent--between the ages of 18-21 have shopped online, according to new research from Forrester. As for teens under 18, many of whom do not have access to credit cards, 52 percent say they have shopped online. The younger set have less than half of what older brothers and sisters have to spend each on the Web: older teens' spending amounts to $193 per month, while younger teens have $76. Older teens are also more familiar with the Web. They spend an average of 15 hours or more online each week and have been using …

MTV has launched a test version of Urge, the long-delayed music store it's operating jointly with Microsoft. The service costs $9.95 per month to stream songs from the network's 2 million-plus song library, and $14.95 for unlimited downloads. If users stop paying the download fee, the downloadable songs will stop working. Permanent downloads will be sold at 99 cents, however. Urge's files are compatible with nearly any music device but Apple's iPod. MTV hopes to set its music store apart with features like 500 preset playlists for different moods and styles, as well as 130 Internet radio stations and 24 …

The results pages of some of the Web's biggest search engines are littered with so-called search engine spam. Link farms, click fraud in sponsored listings, and links to sites harboring viruses and spyware are among the many concerns facing search engines today. A new study from SiteAdvisor, a unit of anti-virus giant McAfee, says that roughly 5 percent of the results found on the first five pages at major engines like Google and Yahoo exposed users to viruses and spyware. That includes 3 percent of normal Web search results and 9 percent of paid advertisements. As The Wall Street Journal …

Yahoo no longer has any interest in producing television-like content for the Web, company CEO Terry Semel reiterated Thursday. Two years after hiring Hollywood big shot Lloyd Braun for exactly that purpose, one wonders what, exactly, Braun is up to these days. In 2004 Braun was hired by Yahoo to run its media group; the company then decided to move its content units to Hollywood country at MGM's former headquarters in Santa Monica, Calif. However, it would appear as though these shifts have yet to bear any fruit. In Kevin Sits from the Hot Zone, Yahoo only has one original …

One of my favorite Google apps is Google Earth, the Webby Award-winning 3-D map of the planet generated from digital satellite images. The coolest thing about Google Earth is that we know there are so many more things the search giant will do with it. We got an inkling as to what that might be at the end of last month, when Google released a free, popular 3-D modeling program called SketchUp. Apparently, Google is asking developers to build 3-D layers on top of Google Earth; it's even hosting a development page for them, called 3-D Warehouse. Is Google creating …