What problem is most likely faced by an advertiser who specifically works through an ad network?

I believe the answer is: Calculating ad traffic and costs

When advertiser rely only on ad network, the amount of payment that they should made would be based on the impressions that the ads made from the visitors. So, it is important to calculate ad traffic in order to find out whether the interest that displayed by target market is worth the cost that they made for the ad campaign.

Idkk take a guess i am no

Early 18th century british industries were generally small scale and relatively unsophisticated. most textile production, for example, was centred on small workshops or in the homes of spinners, weavers and dyers: a literal ‘cottage industry’ that involved thousands of individual manufacturers. such small-scale production was also a feature of most other industries, with different regions specialising in different products: metal production in the midlands, for example, and coal mining in the north-east.two illustrations of 18t