I don't think that's inherently true at all, it depends on the nature of the industry or company and how they're structured.
Most of the fastest growth tech companies required very little labor compared to their early extreme growth - most such companies only got bloated at the tail end of their growth, and their labor to sales ratios fell dramatically (eg Microsoft, Intel, Dell, Cisco, eBay, Google, etc).
Amazon requires less jobs per dollar of revenue generated, than Walmart (~75% less) or Target (~66% less). Amazon will likely push this to an extreme over time as they heavily automate their warehouses with robotics, doing away with at least half of their theoretically expected human labor growth.
Advertising and look-up systems online require vastly less jobs than old-fashioned white / yellow pages.
e-brokers require a lot less human labor than the old brokers used to, where you needed a human to process every trade.
Craigslist butchered the classifieds industry, drastically optimizing it.
eBay was famous for generating massive sales per employee in the first X years of existence, far beyond anything established big auction houses managed.
Microsoft practically invented the software company, and required a lot less labor per dollar of sales than just about any other company you could have compared it to at the time. They also had extreme growth. In 1980 they had the inflation adjusted equivalent of perhaps $40 million in sales with just 40 employees.
This list keeps going.