Interesting. I can tell immediately whether the shampoo suits my hair. For years and years I was using 3 times more conditioner than shampoo and it never struck me why until a few years ago (after switching to Tigi I mentioned above). Nowadays I use a lot less conditioner about 70% less. These days I go through the shampoo bottle faster than the conditioner. Admittedly I have stopped using over the counter bleach products and colourings and only use pro products and a very low peroxide which has also made a massive difference to my hair and better still I'm able to get everything wholesale and at a fraction of the cost. Having tried most the the QVC offerings in hair care and paying the premium, likewise with their skincare, it wasn't until I became really curious to try other brands that I finally found what suits and more importantly what doesn't. ESPA (my skincare of choice) are bringing out a haircare range 1st Feb and I'm tempted to try that but the odds it will beat what I'm currently using is slim to none lol