I suspect many would not feel comfortable with lawyers "chasing" or cold calling to hire them for a claim, Maria. Especially those who previously acted in a non independent capacity, leading to conflict of interests with developers and/or Banks, and who failed to act with all due diligence and who now proport to be experts in this field.
There sadly appears to be a failure to use trusted and regulated accreditation in Spain, such that those legal firms who bring the profession into disrepute or act in an unethical way are adequately regulated and deterred from continuing with such abusive practice(s).
My conception is similar to yours Maria, in that cold calling or using invasive methods of this kind would be perceived as unethical, not to mention alienate and deter in that process.
In this day and age, the psychology of increased "cold call" marketing using these techniques tends to alienate and work against an intent to gain business, hence in the UK the need to sign up to the Telephone Preference service or in the case of unwanted emails to retain an ability to "unsubscribe".
It is sad that the Ethical Code is not more strictly controlled in this regard and I personally would wish that the Bar Associations in Spain would recognise that good regulatory practice with effective deterrents and more transparent complaint procedures has the potential to enhance Spain's real estate industry, and subsequently act as reassurance that legal malpractice and/or invasive methods were being proactively tackled.
But putting all that aside Maria, your reputation as an effective and ethical legal firm who have not only developed the expertise and courageously tackled the Banks during these recent years,(acting as an innovator), plus your intent to educate through this forum, should stand in good stead! 