The Thinkbox Profit Ability research suggests that the traditional distinction between brand and performance advertising models may not be the most effective way to evaluate advertising payback. According to Jane Christian, Managing Director Analytics & Insight at EssenceMediacom UK, it is more beneficial to consider scale efficiency and time as the dimensions that should guide the optimal media mix. The research implies that moving away from the brand-performance distinction could lead to better advertising strategies.

It is recommended to move away from the brand-performance distinction in advertising because this distinction does not neatly operationalize in practice and may not accurately reflect how advertising actually yields returns. The focus should instead be on scale efficiency and time, which are more relevant dimensions for determining the optimal media mix. Moreover, when it comes to budget allocation, performance marketing tends to dominate due to its immediate results, which can overshadow the importance of brand marketing that contributes to long-term success.

Media carryover refers to the lasting impact of advertising beyond its immediate effects. The significance of media carryover in advertising effectiveness is that while all media types 'perform' in both the short and long term, some have a greater carryover effect, meaning they continue to influence consumer behavior over a longer period. This is an important consideration for advertisers when planning their media strategy, as it can affect the long-term return on investment (ROI) of their campaigns.

According to the text, the old rule of thumb that the full impact of advertising is roughly double the short-term impact seems to hold true. This means that the long-term effects of advertising campaigns are significant and can be approximately twice as impactful as the initial, short-term results. This highlights the importance of considering both immediate and prolonged outcomes when assessing the effectiveness of advertising efforts.