Much has been made of Twitter’s increasingly rocky relationship with third party API developers, not helped by some historical inconsistencies in the company’s policy towards external clients, particularly when much of what we know and love about Twitter was created by people outside of the company (including users).

Despite what some are seeing as a veiled threat, many believe that Twitter would never completely cut themselves off from third party, non-official apps and clients simply because the backlash would be enormous. I mean, all those HootSuite, Tweetbot and Echofon fans would go nuts, right?

Perhaps. Perhaps not. It really boils down to one pretty basic question: how many people use Twitter’s own apps?

Step forward Benjamin Mayo, who collected and analyzed one million tweets across a nine-hour period on July 18th to identify the clients behind them.

And the results? After stripping out non-client tweet suppliers such as Instagram and the Tweet Button, Mayo discovered that more than 77 percent of tweets were sent by official, Twitter-sanctioned clients.

Read Mayo’s report for the full list, but here’s your top 10.

Seven of these are official Twitter properties (Keitai Web is Twitter’s Japanese client). Only UberSocial for Blackberry (who knew that was so popular?), Echofon and Twicca are third party.

Tweetbot ranks a lowly 20th overall, and HootSuite comes in below Twitter’s SMS delivery feature (listed as txt in the table) in the 25th spot. And Twitter’s latest Nokia app? It didn’t show up even once in the entire sample.

A caveat. One million tweets might seem like an awful lot but, as Mayo himself notes, it’s a drop in the ocean of Twitter’s daily turnover (which is now more than 340 million). We’d need a much bigger study for this to be really definitive. But this is certainly enough to make this data interesting.

And, for third party devotees, it’s something to worry about. As Mayo concludes, with less than a quarter of tweets coming from apps that use non-official clients, Twitter could ban third party clients “with ease” and with minimal backlash. Most of these folks would simply move over to an official app – there’s every chance that the app they use now is simply the first one they found or liked on the Apple or Android stores.

So, it’s only going to be the Twitter aficionados – you know, geeks – who kick up a fuss. And yes, those geeks can be loud, but relatively there are so few of them that most people (i.e., everybody else, including those already using official products) likely won’t care.

And for Twitter, with all that ad revenue at stake, that’s the bottom line.