A pleaser is essentially a teaser bet that swings the line more in favor of the sportsbook. As such, the bettor gets a bigger payout if they win.
For example, let's say you took the Detroit Lions +6.5 and the Arizona Cardinals -2.5, and wanted to put those lines into a teaser/pleaser. The normal parlay payout on those two teams combined would be +265 for those two point spread bets.
A six-point teaser would swing the lines to Detroit +12.5 and San Francisco +3.5. The payout odds would drop to -134.
A six-point pleaser would swing the lines to Detroit +0.5 and San Francisco -8.5. The payout odds would increase to +700. Pleasers work somewhat like odds boosts, but at the expense of taking a parlay with less favorable lines.