Here we have Cadbury's entrance into the "chocolate bar filled with bubbles" category. As far as I know, the first bar to attempt this marketing angle was the Aero bar, and since then many treats have attempted to enter this field. I'm of two opinions when it comes to air filled bars. I think that this type of bar melts a little faster in your mouth, because there is more surface area to heat contact. But I worry that some candy companies go this route because they feel that they can sell you less chocolate for the same price.
Bubbly is most certainly a bar that uses the bubbles for texture and doesn't seem to be cheap at all, I say this because the quality of the chocolate is so good. It seems like Cadbury is using the bubbles as a texture, and not as a cost savings method. If they were just trying to be cheap, I think they would have used a lesser quality chocolate as well.
The thick solid chocolate coating on the top of the Bubbly, suggests that they didn't go for cheap at all. The bubbly texture really plays a part in eating this treat as well, even for my fingers. When I was holding this bar, my fingers would melt through the chocolate and I could feel the bubbles popping. It was a great unexpected bonus.
Cadbury also uses a fun shape for this bar, it looks like bubbles. The bar also has an uneven thickness, so some of the bubble texture was more predominant, while other bites had less noticeable bubbles. The variation works really well.
My opinion is this, if you're bar has bubbles and crappy chocolate, you're being cheap. If your bar has bubbles and exceptionally good chocolate (like this bar) then you're using the bubble texture to its full potential.