Results from a new LinkedIn Research Network/Harris Poll show that advertisers are not sold on the effectiveness of Twitter for promoting products. Only 8% of advertisers and U.S. adults consider Twitter very effective for promoting products and ideas.

Other nuggets from the poll:

• Just under half of advertisers (45%) say that Twitter is something is in its infancy and its use will grow exponentially over the next few years.

• One in five (21%) believe Twitter will not move into the mainstream and is something mostly young people and the media will use.

• Just under one in five advertisers (17%) believe Twitter is already over and it’s time to find the next best thing.

• 17% of advertisers say they don't know enough about Twitter to have an opinion on it.