Bit of a mouthful to say but there are some really good reviews for this primer and it is different from other silicone based primers as it uses Hyaluronic Acid.
"I think £19 is a really great price for this primer especially when you compare it to the likes of Benefit POREfessional which is £24.50 for only 22ml, and I can honestly say the Deciem Hylamide HA Blur is a much better primer, with such impressive instant results." Quote from here
I started to look at the reviews on this as it was recommended in Escentual mag. Finding it today at this price I thought it was too good a bargain to not give it a go.