Following the Z10's US launch last week, a Goldman Sachs analyst has called BB10's American debut "disappointing" and downgraded BlackBerry's investment rating from 'buy' to 'neutral.'

"While we thought the international launch was solid, the US launch is critical for BlackBerry’s ultimate success," said Goldman Sachs analyst Simona Jankowski in a research note.

"Our retail checks at over 20 store locations since 22 March, including at AT&T, Best Buy and Radio Shack, revealed a surprising lack of marketing support and poor positioning of the product. We also saw limited advertising around the launch."

Sell out tour

Jankowski went on to note that the handset itself was relatively well received by sales associates and reviewers, but sales were sluggish.

"Sell-through at most locations was less than ten per day, and in many it was as low as two to three per day."

Citigroup is also reporting slow sales, estimating that fewer than 5 percent of stores nationwide sold out of BlackBerry's latest smartphone.

As such, there will be keen interest when BlackBerry releases its latest earnings report tomorrow.

[source: Wall Street Journal]