As a Star Wars kid I watched the movies and read the comics. The Phantom Menace and A New Hope were the only movies I saw at the time, then while buying comics, I was reading Enemy of the Empire and just fell in love with Boba Fett for no reason other than he looked cool. Oh and he fought against Darth Vader in that comic.
So I saw The Empire Strikes Back and Return of the Jedi after that, and I was really disappointed at how he died. Properly the only thing I find wrong with him is he fell into the Sarlacc, three times! Once is enough. Still I was glad to hear he lived.
Boba was a Star Wars character I prefered seeing in the comics rather than movies. He just had this massive influence on me. When I saw Attack of the Clones as a kid, I thought the film wasn't that exciting, until we got to Jango Fett!

But he died too quickly.
I recently saw a preview of The Force Unleashed II comic on Dark Horse. It begins with Boba in an apartment with his current girlfriend. WIN. I might read the comic, only because Boba was in the game for less than, 30 seconds, and the comic has more of him.
But I'm babbling on here. Wrap up. We never first see the potential popularity of minor Star Wars characters. Boba Fett did nothing other than look cool, now he is popular, Aurra Sing only had 3 seconds in episode 1 and now she is really popular, and A'Sharad Hett was only of the coolest jedi that started as a minor character, but eventually became popular enough to be, Nah I won't spoil that if you haven't read Legacy.
When it comes to Star Wars characters, people care more about the characters who arn't Jedi or Sith. But we need more Han Solo type characters, SOMETHING THE PREQUELS NEEDED!
Short Version: Boba Fett is like Soundwave! He's just cool.