What happens if Donald Trump comes after your company on Twitter?

A $US4 billion loss if you're Lockheed Martin. An opportunity to promote your startup company, if you're Ryan Holmes of Hootsuite.

And what happens if you're putting yourself out there as a thought leader advising companies on how to build brands on social media, but you tweet a lewd suggestion to a reporter whose story you don't like? Nothing much good, as Ryan Holmes knows. More on that later.

Holmes, a 42-year-old uni drop-out and Canadian corporate pin-up, has built a company he claims is worth more than $US1 billion on the back social media.

Everyone else saw disaster, the day in December Trump's tweets about cost over-runs on the F-35 fighter jet build by Lockheed Martin wiped $US4 billion off the company's stock value. But Holmes, ever the salesman, saw a marketing opportunity.

His book The 4 billion Dollar Tweet, out in April, promises the low-down on how social media and "influencers" have the power to move markets, and "how businesses and leaders risk becoming obsolete if they're not social".

He has been an entrepreneur since his teens with paintball, restaurant and web design businesses behind him. In 2008 he started Hootsuite, offering tools for companies and individuals to reach customers and build brands by managing multiple social networks. In September 2014, Hootsuite raised $60 million from investors at a reported valuation of $US1 billion.

The company boasts 15 million customers, including 836 among the Fortune 1000 Companies. Amid speculation it will go public later this year, he offered his top tips on social media traps for unwary business leaders while in Sydney on a promotional visit.

1. Crawl and walk before you run: "Get educated before you get involved" on social media, he advises. People often don't know where to start, or they fear "messing up" and leaving something "out there hanging on and being misinterpreted". He suggests they remain on the sidelines for a while before dipping in. "It's hard to mess up when you're just listening".

2. Respond rapidly to complaints or criticisms: Slow or declining response times on Facebook pages is a "real factor" affecting brand image, says Holmes, which is why more companies now post their average or expected response times for customers on Facebook.

3. Invest in social media. "This is how customers are choosing to interface with you." So social media needs to be given appropriate management resources. "It is not just something you can give to an intern and have them go away and work on it in a basement".

He would say that, wouldn't he. But even Holmes is not immune to "messing up". In a widely reported incident, he got into a stoush with Bloomberg reporter Gerrit De Vynck early in March over the reporter's story suggesting the oft-quoted but fuzzily sourced $US1 billion valuation for Hootsuite when it raised funds in 2014 was too high.

The real figure was a few hundred million dollars lower, De Vynck's report said.

Holmes tweeted in response that Hootsuite was "definitely north of 1b today".

De Vynck tweeted back with his phone number, noting that Holmes hadn't responded to his request for a conversation before the story was published.

In a retort tweet that was deleted after BuzzFeed got on the case, Holmes suggested De Vynck call him on a sex hotline number that spelt out "1-800-EAT DICK".

Holmes has since tweeted two apologies. The first to De Vynck said "Sorry, wrong number". The second - 17 hours later - said "Apologies on an attempt at humour today. It was offside."

"I let my pride for what the Hootsuite team has built get the better of me", Holmes told Fairfax Media.

He said his comment was not reflective of Hootsuite's culture of diversity and inclusion. "I've learnt to be more considerate in my choice of words, and that when you make a mistake, the best thing you can do is apologise, and own it."