One of the interesting side effects of loosing a whole bunch of weight is being asked how you did it. Typically it's accompanied by a loud exclamation of "you got to tell me" and a disappointment look when you say something like "nutrition and exercise", because that's not what the average person wants to hear. The average person wants a "secret". A "miracle solution" that would end all their weight wows once and for all.
But then there are the other people. The ones who pull you aside quietly and ask you to tell them how you succeeded in doing what they've been failing to for so long. Those are the ones that you look at and think "You might just have the determination and the drive to do it right".
And then you tell them how you did it. You tell them about Spark, about tracking everything. About exercising ("I started out walking 15 minutes a day, now I ran 10 Ks.) About reading labels. About making choices. About all those little things that make up the big change.
And you got to tell them about the good things, too. About how tracking everything means that there really is nothing you "can't eat". Or how you snack more now than you use to, but you snack on different things. About how you are not hungry at all (blunt lie, for most of us in the process, but the point is to encourage) and you've actually discovered new foods through this.
And they listen, and they node, and they take the little piece of paper with the site address you wrote for them, and they promise to check it out. And you node, and smile, and walk away. And you're almost certain that they'll never go through with it.
But you keep talking to people, and you keep advertising the site, and you keep encouraging people to take the first step. Because eventually, one of them would. And after the first step, they may take the second, and the third. And one of these days, you may bump into them in a party, 40 lbs slimmer, and talking to some other person about "this great website you just gotta try..."