Pitched as an online storefront for environmentally-friendly (electric) scooters.
Assumption: Scooter owners care about the environment and will prefer electric scooters over gas scooters.
Learned: (1) Functional transportation and "cool factor" primary motivation for buying (2) Environmental concerns unimportant, people uncomfortable with electric models (3) Trial key stage of buying process.
Pivot: Rent-to-own agreement for Vespa scooters to offer low-commitment trial of product.
CustDev: Over 40 in-person and phone interviews with scooter dealers, sellers, buyers, LSM participants, and people minding their own business in Starbucks. Used Craigslist to get phone interviews with local buyers and sellers.

Pitched as a dashboard for small businesses to understand growth opportunities around a geographical location using heat maps.
Assumption: A new retailer is primarily interested in customer demographics when selecting business locations.
Learned: 1) Static census data is not sufficient, 2) small businesses want business domain-specific metrics, 3) they want to know how their neighborhood is changing, and 4) well-established businesses, not just startups, showed interest in OnRamp.
Pivot: Shifted emphasis to a "business dashboard" which includes data elements beyond mapped census data: traffic, neighborhood "buzz", rent per square foot, market penetration for a specified customer segment, etc.
CustDev: Interviewed over 30 prospective users including Fortune 500 product managers, small business owners, restaurants, real estate agents, and market researchers.

Pitched as a user-driven group buying platform, allowing users to start group-buys for items they want to purchase.
Assumption: High volumes are needed to provide discount and retailers are sitting on inventory that they are eager to move.
Learned: Retailers are willing to provide discount at low volume and they work with suppliers to manage inventory or supply large orders.
Pivot: Allow minimum size of the Mob to be low and target suppliers to fulfill orders.

This group pitched a reputation system for online communities and blogs. After interviewing bloggers they scratched that market segment, finding their sweet spot with community managers and getting two potential customers to sign Letters of Intent and agree on a price of $200 / month.

This team pitched a "Priceline for Tourguides" allowing users to pick their tour and name a price. They spent the majority of the weekend going on any tours they could find and interacting with guides and tourists.

Pitched as an "OpenTable for Small Business," initial assumption was that IT support businesses required better scheduling service. After calling users of a competitor's service, IT repair technicians, and leveraging a LinkedIn survey, this team discovered that open-ended appointment times posed a key challenge. The team pivoted and found a compelling need in service providers with fixed-time appointments such as dog walkers, trainers, and yoga instructors.

Pitched as a "99designs for small business to get marketing advice from students."
Assumptions: College students want extra cash and businesses want ideas on how to solve their problems.
Learned: (1) College students more interested in real world experience and internship opportunities and (2) businesses need their problems solved, not ideas on how to solve them.
Pivot: From crowdspring for businesses ideas to an internship matching website where potential interns apply by writing solutions to a business's real problem. This creates real world experience for the intern during his search that can be saved as a portfolio and offers a more rich internship experience.