Much to the disappointment of many people yesterday, Twitter co-founder Evan Williams did not unveil a new and much-anticipated advertising platform during a SXSW presentation. Instead, he introduced a new service called @anywhere, which while interesting wasn’t what the audience expected or wanted.

So while Twitter continues to work away to create a viable revenue model, here’s one take on how Twitter is going to make money – an approach called “The Five A’s”.

1. API: Twitter recently disclosed it will charge for “Firehose” access to its API. While the company had already been quietly charging for the API, Twitter finally came out with a plan that made sense given the value and amount of data used by third-party services. You can expect Twitter to roll out more API packages.

2. Advertising: An platform based on relevant and contextual advertising is another no-brainer. While Twitter had resisted the idea, resistance proved futile so advertising will become a reality at some point soon. Unless it’s over the top, Twitter users won’t complain.

3. Acquisitions: With more than $100-million of venture capital, Twitter can easily make several strategic acquisitions to expand its portfolio of services – services that could generate revenue. The potential targets include twitpic, Tweetdeck, Seesmic and Twitalyzer.

4. Affiliates: Twitter could generate revenue by entering into affiliate agreements with other service providers looking to tap into Twitter’s audience – sort of like what Wordpress does withits hosting partners.

5. Alliances: Along the lines of what Twitter has already done with Google and Microsoft, Twitter can drive revenue by entering into partnerships with larger companies that want to offer Twitter as part of their services. This is kind of alliance that could involve services such as @anywhere.

Any other ideas on how Twitter can make money?