Theodore Karkoulis | Ethersense: Building the Future of Smart, Energy-Efficient Hospitality

Convert Group is a retail-tech SaaS scaleup born in Athens, with offices in London, and now active across 12 countries (from Greece and Spain to Germany, Czechia, South Africa and more). We enable leading retailers to monetise their data to their suppliers, unlocking incremental revenues, boosting Retail Media budgets and enhancing trust in their industry ecosystem.

We saw early that retail should not be the only revenue stream for retailers. Data & media are goldmines. Retailers have oceans of data but no direct revenue from that asset. Brands were desperate for transparency but had no access in near-real insights, with actionability and ease of use. The gap was obvious: create a trusted platform where both sides could collaborate on data, fairly, securely and with common benefit. That’s how Convert Group was reborn as a retail tech SaaS: out of frustration with the lack of data visibility, and a vision to make commerce smarter, more ethical, and more human.

Convert Group was founded by myself, Panayotis Gezerlis, in 2014 as a consultancy and soon, Elena Chailazopoulou, my first employee, became a co-founder. She is the one that leads our product division, in what today is our sole business and focus. We met in an AUEB university event about 15 years ago, and we have been working together since.

We chose product over services (SaaS over Consulting). Back in 2016, everyone said “stick to services, it’s safer.” But we went all in on product. Painful transition, yes. But today, our SaaS model is what allows us to scale globally, attract leading partners and stand shoulder-to-shoulder with giants like NielsenIQ and IQVIA.

Relevance didn’t just invest capital—they invested belief. They’re not passive shareholders; they’re sparring partners, and sometimes the magnet that attracts trust in the retail-tech & data investing community. Beyond financial firepower, their biggest gift is perspective.

The outdated assumption: Retailers must keep their data locked up like treasure in a vault.
Our proof: when shared responsibly and transparently, data creates trust. And trust creates mutual growth. Retailers generate new revenue streams, brands optimise campaigns, and—most importantly—consumers get better experiences. It’s not “my data vs your data.” It’s shared intelligence.

“Climbing"

Because like my son in his climbing competitions, building Convert Group is about endurance, grip, falling and getting back up, and always aiming for the next hold. It’s tough, thrilling, and addictive. And when you reach the top - even for a moment - the view is worth every scraped finger.