The agency won the retained brief following a competitive pitch and will cover a consumer drive aimed at helping growth in the UK.
It will also handle corporate comms, tackling issues on the daily deals market and b2b work aimed at getting daily deals companies to use the aggregator.
The Danish start-up sources deals sites including Groupon, Living Social and KGB Deals.
PRWeek understands that a key part of the brief will be emphasising to consumers that Bownty will give a targeted offering tailored to the individual.
Rooster will aim to position the brand, which launched in the UK last summer, as a source of expert knowledge on the ecommerce and edeals industry.
The agency’s MD James Brooke said: ‘Bownty wants to address negative perceptions of the daily deals market and emphasise what is positive. While others are pulling back from the market, Bownty is on an aggressive growth strategy.’
The daily deals market came into the spotlight recently when Groupon founder and CEO Andrew Mason was ousted in February.
The move came after the online voucher firm was hit by a 24% slide in its share price on Thursday after posting a quarterly loss.
His departure also came after shares had lost 77% of their value since the firm was floated on the Nasdaq in November 2011, prompting investors to fear the bulk discount deal model was unsustainable.