Normally delivery is £2 @ Figleaves, so this isn't saving you a heck of a lot, but it would encourage me to purchase some of thier smaller priced items. I've bought from Figleaves 2 or 3 times now - really good site. I've also gone through the returns process with an ill-fitting item of clothing - everything went perfect!
The site itself doesn't say anything about the free delivery promotion, but I just got it in an email and it works if you pop anything into your basket.
You should be able to use some of the codes in the voucher section as well for a bit of extra discount...
EDIT - added 10% off link too