The percentage figure relates to the proportion of online messages referring to a specific ad, against all discussions about new TV spots in January. Conversations could be negative or positive but, in terms of noise, British Heart Foundation and Weight Watchers were well ahead of the pack.
The Nielsen TV Brand Effect survey measures the percentage of viewers who can recall the storyline of an ad within 24 hours of seeing it. The "most-liked" table measures the percentage of viewers, among those who could recall an ad, who liked it. In January, there seemed to be little correspondence between rates of recall and affection, as not one spot appears in both tables.
Source: Nielsen TV Brand Effect. Only new ads airing 1-31 January. Minimum sample= 150. Online sample= 2,983.