Life Tree World is just plain weird.
Firstly, it's all built around the fact that people buy "brands". We don't. Most of our friends don't. Well, not exclusively anyway. I like my Kenco coffee, COlgate coffee and Diet Coke, but look in my cleaning cupboards and it's 100% own brand. Same with shower gel (massive fan of the Waitrose essentials one which is £1) and we never buy branded yoghurts, bread, cereals and other cupboard stuff unless it's on offer. We have a Tesco credit card which gives points on ALL spend (not just groceries) and usually convert the points into Pizza Express vouchers at 4 x their face value.
From what I understand of this pyramid life tree thing, you have to PAY to join and then commit to buying from their limited range of branded goods (which are probably not what you'd buy anyway). RRP is a marketing nonsense anyway - it's a meaningless figure set by manufacturers which allows retailers to make believe they are creating bargains. Along the lines of "RRP £50! Special offer 95p!!" and people think they're getting a fabulous deal. It means NOTHING, manufacturers can conjure whatever price they like out of thin air for "RRP".
I don't "get" how you could make money from this - you're getting cashback, not selling stuff. I get cashback from places like Quidco when shopping for many other things. But I don't have to hassle my friends to sign up to Quidco too.
It's all very odd, very non-transparent and shonky. I wouldn't touch it with a bargepole.