Invoking the spirit of Monty Python’s Trojan Rabbit, Jared Wilson points out the problem with ‘bait and switch’ forms of evangelistic activity, whether the less mature forms associated with youth ministries or the more sophisticated forms utilised by attractional or seeker focussed churches.
The problem is:

“the gospel of Christ’s finished work became relegated to the end of a service, almost an addendum to the real focal points of the goings-on, and then it frequently became pushed to the end of an entire message series, eventually became saved just for special occasions, and ultimately has been replaced altogether by the shiny legalism of moralistic therapeutic deism.
Eventually the attractional church became all bait, no switch. The approach of today’s attractional church is like the Trojan Rabbit of Monty Python’s Arthurian nincompoops–smuggled inside the castle walls with nobody inside.
As a result so many inside the system, shepherded under this system and joined to it, can’t distinguish between attractive and attractional, practical and pragmatic. When we lose the centrality of the gospel, we lose the ability to think straight.

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Another sign of this is the preaching in these contexts can be biblical, but largely therapeutic or educational (focused on the needs and actions of the hearer), rather than focussed on what Jesus has done for his people.