Twitter is widely expected to announce and launch their new in-house advertising platform this month; it was initially expected to be announced at the SXSW event, but that turned out to be incorrect. Although Twitter hasn't officially confirmed that this advertising platform will be released this month, the entire microblogging industry has been watching the company closely to see how they'll monetize and how they'll pull off advertising, if that's the road they choose to go down.

Of course, the rest of the microblogging industry hasn't just been sitting idly while waiting for Twitter to get off its duff. Plenty of third-party companies have taken the initiative to offer services for Twitter that the microblogging platform doesn't offer itself. Obviously that includes creating all varieties of Twitter applications, including some stellar clients, but that also includes creating Twitter advertising networks.

Countless companies have sprang up to fill the void in Twitter-based advertising, including Magpie, one of the first Twitter-based ad networks, which "enables advertisers to create relevant, controlled and individualized sponsored conversations in a mutually beneficial partnership between advertisers and twitterers."

Magpie's website spells out their advertising strategy: "Magpie is the leading advertising network for Twitter. We're committed to providing a network that is accessible to business of all sizes, and as such our program has the capacity to support large-scale global branding initiatives down to low-budget campaigns. With a current reach of over 10 Million twitterers world-wide, Magpie has twitterers in all major twittering countries tweeting across a broad range of topics."

Now that Twitter is on the verge of announcing their own built-in advertising platform, though, will advertisers like Magpie be left out in the cold? Probably not - at least, not at first. Twitter's creation of an advertising platform is essentially a huge endorsement of Twitter-based advertising, giving the companies already in the industry no small amount of validation.

Furthermore, the huge size of Twitter's userbase (by some estimation, larger than 10 million users, although how many of those are human, active accounts is a matter of hot debate) means that there's plenty of eyeballs to go around. Companies like Magpie and others have already had months or even years of experience advertising, giving them a distinct advantage of Twitter, who's a relative newcomer to the advertising field. That being said, Twitter will have a huge advantage over them in that they have direct access to the stream of information and aren't subject to any API limits or other handicaps that third-party developers often find themselves struggling to work around.

When Twitter does formally announce and launch their ad platform, some ad networks (particularly the newest ones) might be sent packing. Still others, though, have far too much invested in the industry and the concept to simply roll over, and chances are that there will always be a niche that Twitter's built-in advertising platform doesn't fill, leaving an opportunity for third-party advertisers to prosper.