Learn French: Tu te laisses facilement manipuler par ce marketing. - You easily let yourself be manipulated by this marketing.

The construction se laisser + infinitive is a common French alternative to the passive voice. Even though the meaning is passive (you let the action happen to you), you must use the active infinitive of the action verb. You do not use être + past participle in this structure.

Why is the adverb facilement placed between laisses and manipuler?

In French, short adverbs and adverbs ending in -ment usually go immediately after the conjugated verb (laisses) and before the infinitive (manipuler). Placing it at the very end of the sentence would sound unnatural, which is a common trap for English speakers.

Since this isn't a standard passive voice sentence with être, why do we still use par?

Even though we are using se laisser to avoid the formal passive voice, the sentence still expresses a passive idea. We use par (by) to introduce the agent doing the action (ce marketing), exactly as we would in a standard passive sentence.

What role does the reflexive pronoun te play in this structure?

It acts as the direct object of laisser. You are 'letting yourself' undergo the manipulation. In the se laisser + infinitive structure, the reflexive pronoun always matches the subject who is allowing the action to happen to them.