I AM not by nature an optimist.

It's something to do with the '78 World Cup. Or the 1983 General Election. Or the '87 one. Or the '92 one. Despite the scars of those events, I allowed myself a smidgen of optimism during the Wimbledon final.

I was spending that gorgeous summer afternoon in a hotel room with 25 other people. That may sound like something out of Russell Brand's wilder imaginings but it was in fact a digital training session for Yes Scotland volunteers in Aberdeen.

I'm used to Yes Scotland being ahead in the digital space. In the past few months we have opened up healthy leads over the No campaign in every social media network. Of course, it's hard to keep track of the No camp given its tendency to split.

In any case, at current prices, we are 12,000 "likes" ahead on Facebook and have 7000 more "followers" on Twitter than the largest of the No campaigns. Not everyone who "follows" or "likes" Yes Scotland agrees with us but it's important for our campaign to engage with everyone who is interested in the referendum.

We are delighted to be asked questions. On the Yes Scotland website, we encourage people to send in queries and challenges, which we then publish answers to. The most recent exercise saw 1200 people sending us questions. And we make a point of entering into discussion with supporters and non-supporters on Facebook, Twitter, KIltr, LinkedIn, and so on.

A study by the respected social media monitoring firm Brandwatch shows that 72% of people online in Scotland discussing the referendum are in favour of independence. Of course, that doesn't mean that three-quarters of all Scots using the internet support us. That just means that people who agree with us are more vocal and articulate in discussions online.

However, what gave me my sunny sense of optimism on that day in Aberdeen was that we were making those large and impressive-sounding digital numbers mean something in the real world. The bottom line is that social media activity alone is not going to persuade people to vote Yes.

Our mission at Yes Digital is to make sure our supporters have the information they need to put the case for Yes convincingly in digital and real-world conversations. To do that we need lot of committed, dedicated and intelligent advocates online to make sure our messages are disseminated to the people they need to reach.

There is nothing particularly revolutionary about this. "Word-of-mouth" has been a key campaigning tool since Socrates was a boy. However, Barack Obama's digital teams made an art form out of connecting social media discussions with on-the-ground activity.

In a whistle-stop tour of Scotland that weekend, I trained more than 80 of our volunteers on how to use social media to maximum effect. That was just the first tranche of people with a specific interest in social media. And Yes Scotland has tens of thousands of volunteers.

What impressed me was that Yes supporters were so committed to making the argument online that they were prepared to miss arguably the greatest Scottish sporting triumph of all time to listen to me bang on about Twitter.

The reason we are ahead in social media is that we are genuinely a grassroots movement. That's why there are so many more people making the Yes case online. We have far more volunteers than those on the other side of the argument. And our people have a positive vision and well-informed arguments to share.

The proof of that is not to be found in numbers but rather in the many voices online supporting Yes in a friendly and engaging way, often in places that are independent of the official campaign, whether on websites like National Collective, Bella Caledonia and Newsnet Scotland or in discussions on Facebook groups and Twitter hashtags. It is the human dimension of a digital campaign the makes me feel optimistic about September 18, 2014.

Stewart Kirkpatrick is Head of Digital at Yes Scotland.