Is there any advantage in marketing my product for £99.99 instead of £100?

It's a wide-spread marketing technique that seems to have been around forever- selling products for £1.99, £9.99, £19.99, instead of £2, £10 and £20.

Presumably the pyschology is that submliminally £99.99 seems disproportionately closer to £99 (or £90) than £100 does.

But surely the technique is so utterly transparent and consumers so wary of marketing techniques nowadays that it is completely ineffective. And worse, by doing it, you risk detering potential customers by coming across as deceptive or dishonest.