It is quite obvious that boutique hotels are in fashion, there is no denial, you only have to do a quick search online.
The advantages of discounts, much higher if you book in advance, is that as well as offering a good price it gives us the opportunity to visit many hotels that are normally over our budget. An example, booking a 4 star hotel in Barcelona or a boutique hotel in Serrano Street as low as 60€ per night…
The only condition is that you book through the official website of the hotel, the rates are exclusively online, as the main urban hotel chains in Spain are strengthening their direct online sales and they keep the best hotel rates for their online clients, even if online travel agencies, like Booking, say otherwise.
In order to obtain the highest discount for hotels, as well as booking as early as possible, it is interesting to participate in their customer fidelity programs. Some offer already a 5% discount in all their hotels in the centre of Barcelona simply for subscribing to their newsletter. Others go even further, and throughout the year the offer hotel rooms in Madrid with up to 20% discount for an early booking.
A word of advice:
Read carefully all the conditions of the offer, as some of the most interesting are usually non refundable, so you must have very clear the dates you will travel and be aware that, if anything happens, you will not be able to cancel it and will be charged for it.