There is a a good discussion going on over at the New Liturgical Movement about the challenges that traditional Latin Mass (TLM) chapels and churches face in getting started and staying going. As I read the comments I couldn't help but be reminded of our churches, as we face many of the same problems.
Some of the problems listed that hurt TLM parishes included: cliquish behavior and suspicion of "outsiders;" rude and unfriendly people and clergy with axes to grind; bad meeting times and places; and difficulties from the church hierarchy (i.e. hostile bishops), etc. The last one is not really problem in the continuing church much anymore that I am aware of. (It is certainly not a problem in the APA.) But the other ones are challenges that we sometimes face or have had to face as "traddie" Anglicans.
But there was one thing that was not mentioned - or not mentioned much - that I think is really the main thing that keeps us (and probably them) small. And that is that the culture has drastically declined intellectually, morally, spiritually, and in every other way even since I was a kid. What we do as continuing Anglicans is so incredibly counter cultural that, I think, people just don't know what to make of it or us.
Here are some examples: (Note these are mostly liturgical, but there are many other things that we believe and do [moral teaching, for example] that are just not in step with the culture, and so they think we we are very, very odd.)
Most people today do not even read for enjoyment anymore. Then they come to a church like ours where they find themselves reading Shakespeare-like prayers... and they can barely pronounce the words (or they butcher the pronunciation)! And then they hear the priest exhorting them to read the scriptures, and Morning and Evening Prayer at home! What?? They don't even read comic strips!! Why would they read what we're offering??!
Most people today think that artists like the recently deceased David Bowie were great musicians who created profoundly beautiful and interesting music. Then they come to a continuing church and don't know what to make of traditional hymns, or great organ music, or a great choir that sings chant and polyphony.
Most people today think that dressing up in nice clothes (suits, skirts, dresses, etc.) is strange. So imagine what they think of vestments?!
I could go on, but hopefully you get the idea. The bottom line is that we are more and more speaking an entirely different language from our culture, and the contributes to our small size.
Now I am not advocating that we change these things. But I think we do need to at least be aware of the challenges that face us in these areas. They are not insurmountable. Remember that the Church spread all over the world in the missionary era with what were "strange" liturgies, music, and traditions to those whom they preached the gospel. So these things are not an obstacle to growth per se. We do, however, need to try to figure out how we can reach our world for Christ and his Church given our charisms and traditions, and given the state of people and the world today.