Second attempt at posting this.
Ok I've been on a new plan now for a few months, my data was reduced from 8gb to 3gb when I upgraded. Since then I've continually ran out off data a week or longer before I recieve more, I decided to contact o2 hoping to reduce my minutes and increase my data but sadly this was not possible which gave me the idea for the slider tarrif.
Using my tarrif as the example I currently have unlimited minutes and texts and 3gb of data for 21.50 on the slider plan this would set the three sliders to the middle of the bars. Using your my o2 app your tarrif would show the three bars (minutes, texts and data) The three sliders will move simultaneously when the user changes the value of one, in my case increasing my data would reduce my minutes and texts, this would allow the customer to tailor their tarrif to their current needs and if their need change they just have to slide.
This could also free up time for o2 staff as it would reduce the amount of customers requesting a new tarrif. Unless there was different price levels of the slider tarrif to provide higher maximum minutes, texts and data.
I believe this could be a very good tarrif attracting alot of current customer and possible new customers also due to the freedom this tarrif would provide.
Well that was my idea I thought I'd share.