Yahoo Inc. (NASDAQ: YHOO) told the world that it launched its new "Apt" online ad system a few days ago, but was anyone listening? Although Yahoo! called the new system revolutionary, that's also how many of us were pitched the "Project Panama" ad delivery system that turned out to be slightly evolutionary rather than highly revolutionary. What makes Apt different?

Apt is meant to bring intelligence and relevancy to display ads instead of simple text ads, which are Google, Inc.'s (NASDAQ: GOOG) strength and which have added billions to its coffers over the years. When I stopped using Yahoo! Mail years ago, it was because of those non-relevant, intrusive display ads about cheap mortgages, credit reports and other junk that had no relevance to my purchasing intentions. Apt is meant to change that.

First up will be participation by a consortium of newspapers, who have been hit hard in recent years as advertisers move their campaigns online and out of print. Apt will make the process of buying and selling display (graphical) ads as easy as any self-service system on the web, according to the company. It's about time -- Yahoo! has one of the largest user bases on the entire web, and making sure that all customer data is mapped in a way to provide relevant advertising was most likely a massive undertaking. That Yahoo! could deliver this after such a turbulent summer and with a slew of executives recently leaving is amazing. Now, we'll see if it's actually utilized by anyone who still believes in Yahoo!'s power.

Yahoo Inc. (NASDAQ: YHOO) will soon be selling display advertising and even video advertising on the website of the world's largest retailer, www.walmart.com. The companies announced the partnership Wednesday, although terms of the multi-year deal weren't announced.

Wal-Mart Stores, Inc. (NYSE: WMT) indicated that advertisers would be able to buy ad space alongside walmart.com's product and information pages, which brings up the question: will Wal-Mart allow competitive ads to sit alongside its website pages? Display ads are graphic ads, unlike most Google Inc. (NASDAQ: GOOG) ads that are text based.

Imagine this: a customer is looking at a Black & Decker weed trimmer at walmart.com and a full display ad from Target Corp. (NYSE: TGT) or The Home Depot (NYSE: HD) pops up with a competitive model and a link to where it can be purchased. This scenario sounds like it could easily happen here.

It will be quite interesting to see how this partnership is launched and how Yahoo!'s display ads are implemented into walmart.com's website -- and if any advertiser can buy ad space on one of the largest e-commerce sites on the web. Perhaps Yahoo! will financially make it worth Walmart.com's while.

Google (NASDAQ: GOOG) and Yahoo! (NASDAQ: YHOO) have been saying for years that the next frontier for internet-based advertising is the cellphone screen. With wireless handsets having high-speed data connections and really impressive (but small) screens, and with cellphones outselling PCs one would think both companies are right on the money. Not a quarterly conference call with Google can go by without CEO Eric Schmidt alluding to the mobile ad space as a whole new frontier for Google.

When a research firm like Gartner predicts $11 billion in industry revenue from mobile advertising in 2011, that is the kind of figure that makes many stand up and pay attention. But so far, mobile advertising reality is not turning out to be rosy as that. Mobile advertising is an industry worth under $1 billion in 2007; can it really skyrocket to over $11 billion in four years? Most likely, no.

A main reason for this is the incredible complexity of mobile web browsing on the mainstream cellphone (lack of a keyboard, perhaps?). I'm not talking Palm Treos, iPhones and other muscular, do-it-all phones, but the kind the average joe carries in that front pants pocket. Do you know of many people who regularly access the web on their cellphone? Think about it for a second. According to Jupiter Research, only 16% of Americans regularly access the web on all those cellphones. What's going to get that figure up to 50%?

For one, a much less convoluted way for normal phones to hop on the web, making it as easy as web browsing on a PC. It's nowhere near that now, save for a handful of device categories like smartphones and the like. Think text messaging could be the answer? Will customers stand for being interrupted with advertising over text messaging? It's an opportunity that could launch a consumer revolt more than anything. What's left, then? Mobile advertising will get there and indeed win the day -- just not by 2011 and in the numbers predicted.