I love the coupons because they do have Harlequin books cheap like $3.89 where HQ has it for $4.06 and Amazon $3.69 a book then with the coupon $1 off it's like $2.89 at Kobo. So that's where I buy my HQ books from.
However it seems Kobo must of changed credit card processors in the last few weeks because starting this month I'm now charge a foreign transaction fee on all purchases by them. It like 15 to 30 cents per transaction the last 4 books I bought.
I'm in the USA so this probably doesn't apply to those in other countries but something to take in account if you want to know the real price you will be charge and if you use a Debit card or Debit Gift Card to buy with and don't have those extra few cents in there things can get sticky. I went over mine because of this and wound up paying an overage fee with my CC provider. At first it said the amount on the invoice but once the charge was completed a week later the fee was added.
Kobo is still the cheapest around for me to shop for my books once I take the fee into account so it doesn't happen again.