MeseMoa. tend to release a couple of new singles each year, and a new album every year or two. Singles usually come with the instrumental versions of the songs and a DVD with bonus content, such as behind the scenes footage. Currently only the Sesshoseki Session, Karamete and May Say More singles are available for online streaming here.
They usually produce new merchandise for their tours, big one-off concerts, and events like the birthday events. Typical merchandise include T-shirts, towels, keyrings, wristbands etc. Most concerts also have higawari 2Ls for sale, photos which are unique to each concert and may contain a small message from the member featured.
Because they're an independent group, MeseMoa.'s goods and music are only available via their website or by purchasing them in person at events. The vast majority of shopping sites don't ship outside of Japan, and MeseMoa.'s online shop doesn't even accept online payments, so you have to be creative about how you order what you're looking for - check out this page for advice.
Traffic Light.'s music and any merchandise which is sold via a different company (e.g. photobooks) may be available in typical shops like Tower Records or HMV. In this case, they will count towards the Oricon chart, Japan's major entertainment chart.
MeseMoa. usually have a lucky dip at their events, where you pay a set price and could win one of a number of prizes. The way it is set up differs between events, but generally you pay 500 yen to buy a random trading card. Inside the envelope, you may also win a ticket which can be exchanged for one of the following:
Oshi cheki - This is the rarest prize, where you get to take a photo with a member of your choice, and they'll write a personalised message on the Polaroid for you.
Doodle cheki - A random Polaroid which a member has already doodled on and autographed.
Random cheki - Any random, non-doodled Polaroid.
2L photo - A larger photo printed on glossy paper, usually taken in a photography studio or on stage mid-performance.
Since the results are random, fans usually post photos of their winnings in the hopes of exchanging them with others. Some people are very specific about the outfits and poses they want photos of, while others may just be looking for certain members. People generally refer to the members by their member colours when exchanging photos and merchandise. Check out this post for an explanation and example!