The agency, which has offices in the UK, US, Denmark, Sweden, Germany and France, is opening offices in Spain and Italy.
The money will be used to develop its technology, improving its international email delivery platform to maximise rates of delivery.
The company is also committed to developing its Data Quality module, which is designed to eradicate fraudulent leads.
Ben Richardson. the MMC investment manager who oversaw the funding, said: "Clash-Media is well positioned in this market as it allows its customers to clearly measure return on marketing spend.
"Last year, the business grew at over 100% per annum and we think this is a good time to be investing in growth businesses."
Simon Wajcenberg, Clash-Media's CEO, said: "In a difficult financial climate, companies, regardless of their size, need good quality sales leads to generate business and revenue.
"We are finding that now major global blue chips are placing an increased importance on our performance-based approaches.
"In a climate where cash is king, I am delighted to receive this additional funding boost."
The latest round of funding takes the total investment by MMC to £4.9m since the relationship started in June 2007.