The company was the sixth-ranked New Zealand firm in the latest Deloitte Asia Pacific Technology Fast 500, with year-on-year revenue growth of 508 per cent.
Conway said he and wife Emily had just emigrated to New Zealand from Britain when he started the business.
"My wife was a social worker so we didn't have much funds to do it," said Conway. "Fortunately she was up for supporting me and I built the website myself. It was a bit of a comedic affair because I don't have much in the way of design skills."
Falkenstein, who declined to disclose how much The Harvard Group had invested in Pure SEO, said he had found the technology firm's growth prospects particularly attractive.
"Really the rationale [of The Harvard Group] is looking at growth companies which we think we can help at the front end," he said. "If they're high growth, and we can make them grow faster, that's where we think our expertise is."
Falkenstein said only around 32 per cent of New Zealand companies had a website, but the number of local firms establishing themselves on the internet was growing at 45 per cent a year. "One of the big opportunities now is to take advantage of the localised business. We've just started a unique programme with tradespeople and professionals in the SME [small and medium enterprise] market to own their local territories, and this offers a competitive advantage for them and us."
Pure SEO would continue to see strong growth as more businesses ventured online, recognising their customers were increasingly doing their research on the web, said Falkenstein.
Conway said the biggest benefit of the investment was the business experience Falkenstein and fellow Harvard Group director and shareholder Ian Malcolm had to offer.
"They will be actively involved in developing and implementing the strategy for growth, which will be enormously advantageous."
Conway said Pure SEO's main goals this year included establishing offices around this country as well as in Sydney, where salespeople would be on the ground to service new clients.
If the company does go ahead with a stock exchange float it would list on the NZX, he said.
"It's one option, but first we're focused on growth ... our main focus at the moment is customer acquisition."
Conway said The Harvard Group's investment had not introduced any new capital to Pure SEO, which would continue to fund its growth from profit.
Conway said Pure SEO's two main local competitors are SureFire Search and First Digital.