Beats the heck out of me as well. Nokia used to do this really well, every year there would be the new phone to have, so as your 12 month contract came to an end you were onto the next greatest phone. They still made their other phones, but they always had the brand leading phone, whether it was the 2110, 5110, 6110, 7110, 7650, 3650, and so forth. (Showing my age there).
But today, who knows what are the leading phones in some ranges? Certainly not HTC range.