Get on AngelList (angel.co), it's widely used by web and e-commerce investors. Best way to get visibility.

There are several options.

Start by researching on PWC Moneytree and CrunchBase about investors who have funded marketplaces (e.g. Benchmark has invested in several over the years.)

BTW, Greylock just announced (end-Aug 2013) $100M marketplaces fund.

From my conversations, several investors seem to be looking at the marketplaces theme these days.

Happy to talk more, if you'd like to.

When you are looking for capital for your business, there are many options to choose from these days. Today, we will talk about private equity- where you give away shares of your company in exchange for capital. Business angels are individuals, often successful businesspeople, who are using their own funds to invest in businesses they like, whereas venture capitalists manage the pooled money of others in a professionally managed fund. Angel investors and venture capital funds focus on businesses in different life cycles. Angel investors and venture capital funds focus on businesses in different life cycles. As mentioned before, business angels operate individually and sometimes in so called angel groups or angel networks. The amount they invest varies from €10K and €100K- or more when angels group together. Both groups receive shares of the company when investing. However, venture capitalists often require a seat on the board, where business angels will function more as a mentor, to coach and advice the entrepreneurs running the business. Whether you get your investment in the form of venture capital or from angel investors, you are giving away part of the ownership in your firm.
Capital is not the only thing they provide you with. Venture capitalists and angels have a large network which they can introduce you to. Well, this really comes down to the company’s development. If your company is early stage, but friends and family are not an option anymore, a business angel is probably best to look for. The amount a business angel invests will be enough for you now, considering the early stage your business is in.
Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath