Should an experienced copywriter write their own sales copy?

[lisa]

Hello webmasters and internet markers,

If you are planning to launch a new product, will you write your own sales copy or would you hire another copywriter? Or do both to split test?

The reason I ask is because I am not an experienced copywriter and I often have clients were asking me about this and I am wondering if you have noticed increased or decreased conversions by writing their own sales copy?

Please share your thoughts?