Intercity buses in Germany
While most European countries have had a system of long distance buses for a long time, intercity bus travel was virtually nonexistent in Germany until 2012. Things have changed rapidly in the past years, however, and intercity buses now offer budget friendly transport alternatives to a wide range of German and a handful of international destinations.
Understand
For historical and legal reasons, up until 2012 German long distance bus travel was limited to a few connections mostly to and from Berlin and international lines with few stops in Germany connecting them to mostly Central and Eastern-European countries.
Currently the prices are lower than most competing train services, because buses don't pay anything for the use of the roads whereas trains (even those operated by the state-owned Deutsche Bahn) have to pay for the use of the tracks. In the current SPD-CDU "grand coalition" the SPD is in favor of some sort of toll for buses, but the CDU has flatly refused due to it not being mentioned in the coalition agreement signed in 2013. As the next elections are scheduled for 2017, a toll for buses might become an issue only after that or during the campaign.
Generally speaking the buses will be reasonably new and safe for traffic, but the distance between seats is often unsatisfactory for large people. While most companies sell snacks and drinks or make stops at places where you could buy food en route you should consider bringing your own as the selection is very limited. Although Wi-Fi is often promised it is not available in all buses and can be unavailable without prior notice because of a replacement bus being used that doesn't have it. Also, keep in mind that the Internet connection is provided via a normal cellphone signal so bandwidth and access (especially in a full bus) may be limited.
Buses are usually slower than even regional train service unless the connection by bus is more direct. This is mainly due to three reasons. The top speed of buses is somewhere around 100km/h, whereas "low-speed" trains can go up to 160km/h and frequently do so with the help of tilting technology and modernized tracks. High speed trains (which almost all long distance trains in Germany are) of course have top speeds in the rage of 250km/h to 300 km/h and rarely go slower than 200km/h for long stretches. Also, buses have to get into and out of the city for every stop through congested roads, whereas trains simply zip through on dedicated tracks that usually don't slow them down as much. Finally, by law, bus drivers have to take regular breaks (usually 30 minutes for every four and a half hours traveled) so, if due to road congestion the bus is late, an extra unscheduled pause may be taken.
Transporting bicycles
While most companies offer to transport bicycles (provided you pay extra) capacity is usually very limited (hardly more than three or four per bus) and it requires advance notice. Also keep in mind that the "trick" that is common on trains - to take a foldable bicycle or put a bicycle in a bag and declare it normal luggage - is less feasible on buses, as there is little space in the bus and the luggage compartments and excess baggage will almost certainly incur a surcharge. It might work out cheaper and more comfortable to take an IC or regional train (ICE trains do not transport bicycles unless in the ways mentioned above, when they are deemed "luggage")
Prices
Like long distance trains and most flights in Germany, prices for buses are cheapest when ordered well in advance online. Sometimes tickets are sold through other channels (such as discount-supermarkets) as a marketing gimmick, but this seems to not be the case anymore as of 2015. It is possible to buy tickets directly with the driver prior to boarding, however expect to pay up to ten times the (advertised) lowest possible rate. Another possibility that opened up in recent times is to buy tickets at ticket offices at some bus stations. However, those ticket offices usually belong to one brand only and don't sell tickets of competing companies, so you might end up paying a higher price than you would have online. While connecting services with a change of buses are possible, most companies don't guarantee all connections and delays can happen especially during holidays and on weekends as congestion increases during those peak times. If you want to buy your ticket directly with the driver keep in mind that you are not allowed to board a bus when all seats are taken, as standing in the bus is illegal on long distance buses in Germany. Most companies also sell tickets through tour operators and Postbus also sells tickets at most post-offices. However, prices will be if anything higher than the rates online, as there will be some premium for the vendor or the personal service included in the price. Unlike for trains, there are no discounts for frequent travelers and fewer special offers for connecting services.
According to media coverage, the average rate for a bus ticket per person per kilometer was around 4 cents and even lower on some routes with fierce competition. Experts on the topic claim that prices of at least 6 cents per kilometer per person would be necessary to break even. Therefore, an increase in prices seems to only be a question of time and competition.
Companies
The mainly domestic companies are almost all recent start-ups whereas the international companies have been around for a longer time mostly.
Mostly domestic
The market is still very volatile and several companies have already folded. The current low prices are mostly due to the fierce competition among the different companies and with the other modes of transport (especially trains and on longer distances low fares airlines). All of the bus-operators, including Deutsche Bahn subsidiary Berlin Linien Bus operate on a for profit model and don't receive any direct government money (although their free use of roads and other facilities could be interpreted as a "hidden" subsidy) so expect prices to rise when those companies want to break even or make profits in the near future. Currently the following companies exist:
Postbus is a subsidiary of the German postal service. It was formerly a cooperation with the German motorists association ADAC, so you might still see buses saying "ADAC Postbus". Buses are in the signature yellow of Deutsche Post. Postbus usually offers the most comfortable ride and the best amenities, but is also most of the times a little bit more expensive. In a copy of one of the most successful marketing ploys of Deutsche Bahn, Postbus offers a "Postbus Card" that gives a 25% discount on all Postbus tickets and costs 25€ for one year (making it worth it once your Postbus travel amounts to 100€ or more per year). Unlike Bahn Card it ends automatically and there is only the one year 25% option. The Postbus Card also entitles you to one hot beverage per trip with no extra charge.
Meinfernbus Flixbus, a merger of two private start-ups founded after the deregulation of the long distance bus market. It offers the the largest network in Germany with buses and corporate identity in a green color-scheme.
DeinBus has good coverage in the south and southwest of Germany but there are hardly any routes to northern and eastern Germany.
Berlin Linien Bus, a subsidiary of Deutsche Bahn (Bahn Card discounts do not apply), is the only company that has been offering domestic services in Germany prior to 2010 on a larger scale. Although originally all connections went to or from Berlin they now cover most of Germany as well as some international routes.
Onebus is one of the newer entrants to the market
Mostly international
Eurolines mostly serves eastern Europe but has destinations in other parts of Europe as well
IC Bus another recent subsidiary of Deutsche Bahn. They offer very limited international connections to neighboring countries. They are currently expanding their network. Deutsche Bahn rates and prices (including Bahn Card discounts) apply.
Megabus Frankfurt, Stuttgart, Cologne and Munich.
student agency is a Czech company with a network throughout Europe that also serves some domestic routes in Germany. While they don't serve many places in Germany their prices and service (free hot beverages, video screens at every seat) make them worth considering on the routes they do serve. Unfortunately they only offer WiFi inside the Czech Republic.
Stations
As the market is very young, most lines don't operate out of dedicated stations as such but rather go from and to places close to the central (train) station or leave from the regional transport ZOB (Zentraler Omnibus Bahnhof, central bus station) that is often also centrally located. If you don't know the bus stop, check with your online ticket, as it usually includes an address and a small map of the station. Some companies serve more than one station in a city, especially if the city is very big (e.g. Berlin) has more than one major train station (e.g. Dresden) or has a major international airport (e.g. Frankfurt) make sure to be at the right station and for connecting services make sure whether the station where your connection leaves and arrives are the same and if not how to get from one to the other and how much time that takes (unless you are going by light rail/ subway/ tram plan some extra time for traffic-congestion). As of 2014 most bus-stations don't have any services or stores particular to them but as many of them are close to a train station you can use their facilities. In exceptional cases, such as the Berlin bus station, prices at bus station stores seem to be in the same (high) range as prices at gas stations.