Campaign attribution refers to how one should measure a campaign's effectiveness. The question is under what circumstances a campaign should get credit for a specific conversion. Let's say a visitor enters a website through a campaign, but does not convert during that visit. A few days later the visitor returns to the site, but this time he or she enters directly and now decides to complete the conversion.
Even though the visitor did not click on any campaign the second time he/she visited the site, one could argue that the campaign should still get credit for this conversion. After all it was the campaign which brought the visitor to the site in the first place. It was therefore the campaign which enabled the visitor to come back later and convert.
By default, Netminers InSight will not accredit campaigns in cases like this. By default, it will only attribute a conversion to a campaign if the conversion happens in the same visit as the campaign. However, it is possible to change this default setting so that campaigns are inherited across multiple visits. This will typically present a more positive view of your campaigns since all the visitors' conversions that happen after a specific campaign will now be attributed to that campaign.