Lock-in i.e. compelled to buy the same brand when you add more items. Generally, for example, it doesn't matter too much which heart monitor or speed sensor you buy, as they all tend to connect to any GPS. However, we've recently bought bathroom scales. It's really annoying that they can't feed readings to Garmin Connect, because we didn't buy Garmin scales - and were never going to do so, because their prices for the product are (ahem) off the scale. Would have been useful because Garmin tracks weight as part of health measurement. So, maybe move away from Garmin, even though it's what I've bought for everything else so far. As it stands, our scales feed into another system.
I get you, thanks for the reply.