Close to 100 years ago one of the "fathers" of modern advertising taught that it generally took a man 20 exposures to an ad to buy the product [apparently they didn't let women out of the house then, or we couldn't read, or it was illegal for us to carry money and transact a purchase, or something, but that's a different topic :D].
As television caught on 60 years ago and marketing psychology got more sophisticated, the conventional wisdom of the time pared the 20 exposures down to at least 7. But that was when tv only had 2 or 3 channels, you had to actually get up and walk across the room to change the channel -- imagine! -- and it wasn't on 24/7.
Now an electronic marketing message has to compete with all the other electronic media that nearly everyone is plugged into these days, sometimes more than one at a time. Plus, lots of people are pushing virtually the same services without making their unique distinctions crystal clear and without connecting to the emotional suffering of potential clients in any authentic, relationship building way.
Years ago I learned some cool things about developing and giving a signature talk as a way for people to get to know you, like you, and trust you, and thereby want to work with you or refer to you. As an introvert but experienced teacher, I found doing signature talks comfortably like teaching and much more preferable than going to braincell-sucking networking breakfasts (not that those don't work for some, they just never worked for me).
My take on the latest marketing fad about getting out of our caves and into the community is that people are craving live experiences again because we've all gotten overly isolated in our little ipod/iphone/inetbook, rss, tweetme then retweetme worlds. They want to experience our personality, energy, humor, empathy, compassion, knowledge and expertise BEFORE they commit to working with us, and being in the spotlight of a speaking event might be a place where you too can shine and then close the sale.
AND, it's also still quite possible to let your personality, energy, humor, empathy, compassion, knowledge and expertise shine through your website and other writing -- yes, even still on the internet and without having to close the sale -- because the world is not oversaturated with YOUs.
If you aren't one of the millions for whom public speaking is only slightly less objectionably scary than getting buried alive in an ant hill after a honey bath, it can be an alternative way to leverage your time and effort in reaching many people at once rather than schlepping to doctors' offices one at a time with baskets of muffins.
Bottom line, in my view, is that the smart thing to do is to make use of whatever marketing strategies fit your personality and comfort zone the best.