Here’s a look at what we’re reading today at 435 Digital:

Our SEO team is wondering if ALL site link-building tactics are now forbidden by Google?

So we’ve been taught that we need to get backlinks for ages. The old Google Webmaster Help section had something like “get other webmasters link to you” tip which we were all happy to follow.

Now with all those Penguin updates and SEO fear that followed, poor website owners are really lost: Is there any legit way to still build links?

Is there value in a 404 Error? Renny Gleason says “yes,” and our Web Dev and SEO teams agree:

Oops! Nobody wants to see the 404: Page Not Found. But as Renny Gleeson shows us, while he runs through a slideshow of creative and funny 404 pages, every error is really a chance to build a better relationship.

Bing it on: see which search engine results you prefer. You can compare side-by-side search results for Bing and Google here.

Our account managers have pointed out that Google AdWords announced yesterday that they’re rolling out enhanced sitelinks globally, meaning all countries where AdWords is available will now have the opportunity to enhance their ads with additional sitelinks. US users have had this chance since February and have reportedly seen a boost in ad engagement thanks to the increased visibility of their ad/links. Here’s what Google has to say:

Early testing showed that enhanced sitelinks could make ads that appear above the organic search results even more useful. And they could lead to significantly higher clickthrough rates for an advertiser than regular 2-line and 3-line sitelinks.

Over the last several months, we’ve continued to improve the ad systems for creating enhanced sitelinks and determining when they’re most useful. Now, we’ve begun to roll them out in all countries where AdWords is available

A US study on ROI states that the ideal spend on mobile advertising should be 7% of a company’s marketing budget (9% for “higher involvement” brands). With the speed at which mobile is growing, it’s likely this amount will grow quickly in the next several years.

Currently, marketers allocate less than 1 per cent of their marketing budget to mobile advertising. The white paper also stated that mobile’s share of the media mix is projected to increase to more than 10 per cent over the next four years, based on growth in adoption of smartphones only.

“It is safe to say, however, that the growth does not stop there,” the study authors added. “As with all new media, more effective targeting, creative excellence, better ad units, tighter industry standards, innovation in technology and other factors will all contribute to increased spend and the further establishment of mobile in a marketer’s mix.”

As the trend toward mobile devices is too big for advertisers to ignore, Greg Stuart, global CEO at the Mobile Marketing Association, noted that marketers are looking for the optimal way to apply mobile in their marketing campaigns.

“From digital to social media and subsequently mobile, marketers are figuring out how to apply these principles,” he told Campaign Asia-Pacific. “Mobile can help to integrate the marketing plan with tools such as QR, AR and NFC. It connects every channel, from print to outdoor.”

Finally this Friday, with all the iPhone 5 hoopla this week, we especially enjoyed this video, wherein Jimmy Kimmel tricks people outside the Apple store in NYC into reviewing the iPhone 4S. Hilarity ensues: