We have noticed bookings down this year, but having spoken to several people where I live and work, they think it is because the airlines have undercut airfares to other destinations, causing people to try them out.
If you look at prices to Malaga they are far more expensive than other countries. It is just as cheap to fly to America than Spain. We have had several guests who have either booked to land at either Saville or Granada, just to get the cheap flights from as little as £9.00 + taxes., and then drive down to Marbella area. You have to remember that the more properties on La Reseva which are completed, are going to be rented out, thus giving the guest a far wider choice.
When we bought our apartment, we were told by the estate agents (like no doubt others were also told) that the rental potential would be all year round, generating a weekly income of approximately £600 per week in the high season. Great if you can get it. Hey but never the less we only rent ours out to cover the mortgage. If beats the touring caravan we once had.
How many web sites do you advertise on? Have you ever looked at how many are advertising on the same sites. That gives an indication how many there are on La Reserva and still more to come.