Global IPTV (News - Alert) subscriptions are expected to pass the 100 million mark in 2013 and grow to 181.1 million in 2017, according to Pyramid Research.

That means that IPTV’s share of global pay-TV subscriptions will increase from 9.3 percent last year to 15.8 percent in 2017.

The growth is notable but, it should be said, accounts for a slowing clip. "IPTV subscriptions grew at an impressive CAGR of 40 percent between 2008 and 2012," said Pyramid Research associate analyst Guillermo Hurtado. "Between 2012 and 2017, Pyramid Research forecasts that global IPTV revenue will increase at a 16 percent CAGR, reaching $44 billion at the end of the period.”

But as ever, not all markets are created equal. IPTV household penetration levels vary greatly across regions.

The three largest countries for IPTV, which are China, France and the U.S., each had more than 10 million IPTV subscriptions by the end of 2012, and together accounted for roughly 53 percent of the global IPTV subscription base.

The Asia-Pacific region remains the largest IPTV market, accounting for 45.3 percent (38.2 million) of global IPTV subscriptions as of January 2013. However on a per capita basis, Western Europe and North America have the highest penetration rates, at 14.4 percent and 8.8 percent, respectively.

Meanwhile, the lowest penetration rates are seen in Latin America (0.6 percent) and Africa and the Middle East (0.3 percent)