Armenia is part of La Francophonie? Why?

I can't get too excited by the news that Canadian Michaëlle Jean lost her bid to be re-elected as head of the Organisation Internationale de La Francophonie, the organization of French-speaking nations.
That honour, if such it be, went to Louise Mushikiwabo of Rwanda, who seemed to be the consensus candidate, despite the fact that Rwanda recently made English, and not French, as the country's official language and the language of reference for its education system. Yes, Rwanda has its problems, principally its long-time autocratic president Paul Kagame and his tendency to flout democratic rights and press freedoms. But Jean's last 4 years at La Francophonie have been far from controversial, what with her rather high-handed ways, and leadership of the organization tends to be something of an African fiefdom (the bulk of its 54 full voting states regions are in Africa).
What particularly surprised me, though, was the fact that the vote was taking place in Yerevan, Armenia. Armenia? French-speaking? A quick perusal of Armenia's Wikipedia page reveals the official language of Armenia to be ... Armenian, and the only other languages widely spoken by Armenians are Russian and English. And yet, (Wikipedia again) Armenia is in fact a paid-up member of La Francophonie, as indeed are several other unlikely countries such as Greece, Albania, Macedonia, Moldova, Egypt, Qatar and Vanuatu, none if which have French as an official language.
Also in today's news, Saudi Arabia was applying to join the organization,(yup, no French connection there either), an application that was only refused for that country's unfortunate tendency to assassinate dissident journalists, and nothing to do with the fact that they don't speak French. They were only applying for "observer status", but still..
So, what is the requirement for joining La Francophonie? Do they just take any old country that happens to apply? Well, supposedly it represents countries.or regions where French is the lingua franca (no ounce intended), where a significant proportion of the population are French-speaking, or where there is a notable affiliation with French culture. This last item is a particularly vague and woolly one, but even so, where do Armenia and Saudi Arabia fit into this? Probably the best Armenia can offer in its defence is that there is apparently a thriving Armenian diaspora living in France (as there is in several other countries), and, we are assured, French is taught in Armenian public schools (along with other languages).
I'm clearly not the first to wonder at the organization's membership policy. It is a strange beast, to be sure. To take another example, get this: Algeria, with one of the largest French-speaking populations in the world, is conspicuously absent from the membership list (but then France and Algeria don't exactly get along, and have some pretty bad history).
It's all a bit of a mystery.